PMMA-silica hybrid preparation conditions.
\\n\\n
More than half of the publishers listed alongside IntechOpen (18 out of 30) are Social Science and Humanities publishers. IntechOpen is an exception to this as a leader in not only Open Access content but Open Access content across all scientific disciplines, including Physical Sciences, Engineering and Technology, Health Sciences, Life Science, and Social Sciences and Humanities.
\\n\\nOur breakdown of titles published demonstrates this with 47% PET, 31% HS, 18% LS, and 4% SSH books published.
\\n\\n“Even though ItechOpen has shown the potential of sci-tech books using an OA approach,” other publishers “have shown little interest in OA books.”
\\n\\nAdditionally, each book published by IntechOpen contains original content and research findings.
\\n\\nWe are honored to be among such prestigious publishers and we hope to continue to spearhead that growth in our quest to promote Open Access as a true pioneer in OA book publishing.
\\n\\n\\n\\n
\\n"}]',published:!0,mainMedia:null},components:[{type:"htmlEditorComponent",content:'
Simba Information has released its Open Access Book Publishing 2020 - 2024 report and has again identified IntechOpen as the world’s largest Open Access book publisher by title count.
\n\nSimba Information is a leading provider for market intelligence and forecasts in the media and publishing industry. The report, published every year, provides an overview and financial outlook for the global professional e-book publishing market.
\n\nIntechOpen, De Gruyter, and Frontiers are the largest OA book publishers by title count, with IntechOpen coming in at first place with 5,101 OA books published, a good 1,782 titles ahead of the nearest competitor.
\n\nSince the first Open Access Book Publishing report published in 2016, IntechOpen has held the top stop each year.
\n\n\n\nMore than half of the publishers listed alongside IntechOpen (18 out of 30) are Social Science and Humanities publishers. IntechOpen is an exception to this as a leader in not only Open Access content but Open Access content across all scientific disciplines, including Physical Sciences, Engineering and Technology, Health Sciences, Life Science, and Social Sciences and Humanities.
\n\nOur breakdown of titles published demonstrates this with 47% PET, 31% HS, 18% LS, and 4% SSH books published.
\n\n“Even though ItechOpen has shown the potential of sci-tech books using an OA approach,” other publishers “have shown little interest in OA books.”
\n\nAdditionally, each book published by IntechOpen contains original content and research findings.
\n\nWe are honored to be among such prestigious publishers and we hope to continue to spearhead that growth in our quest to promote Open Access as a true pioneer in OA book publishing.
\n\n\n\n
\n'}],latestNews:[{slug:"intechopen-authors-included-in-the-highly-cited-researchers-list-for-2020-20210121",title:"IntechOpen Authors Included in the Highly Cited Researchers List for 2020"},{slug:"intechopen-maintains-position-as-the-world-s-largest-oa-book-publisher-20201218",title:"IntechOpen Maintains Position as the World’s Largest OA Book Publisher"},{slug:"all-intechopen-books-available-on-perlego-20201215",title:"All IntechOpen Books Available on Perlego"},{slug:"oiv-awards-recognizes-intechopen-s-editors-20201127",title:"OIV Awards Recognizes IntechOpen's Editors"},{slug:"intechopen-joins-crossref-s-initiative-for-open-abstracts-i4oa-to-boost-the-discovery-of-research-20201005",title:"IntechOpen joins Crossref's Initiative for Open Abstracts (I4OA) to Boost the Discovery of Research"},{slug:"intechopen-hits-milestone-5-000-open-access-books-published-20200908",title:"IntechOpen hits milestone: 5,000 Open Access books published!"},{slug:"intechopen-books-hosted-on-the-mathworks-book-program-20200819",title:"IntechOpen Books Hosted on the MathWorks Book Program"},{slug:"intechopen-s-chapter-awarded-the-guenther-von-pannewitz-preis-2020-20200715",title:"IntechOpen's Chapter Awarded the Günther-von-Pannewitz-Preis 2020"}]},book:{item:{type:"book",id:"777",leadTitle:null,fullTitle:"Prostate Cancer - From Bench to Bedside",title:"Prostate Cancer",subtitle:"From Bench to Bedside",reviewType:"peer-reviewed",abstract:"The present textbook highlights many of the exciting discoveries made in the diagnosis and treatment of prostate cancer over the past decade. International thought leaders have contributed to this effort providing a comprehensive and state-of-the art review of the signaling pathways and genetic alterations essential in prostate cancer. This work provides an essential resource for healthcare professionals and scientists dedicated to this field. This textbook is dedicated to the efforts and advances made by our scientific community, realizing we have much to learn in striving to some day in the not too distant future cure this disease particularly among those with an aggressive tumor biology.",isbn:null,printIsbn:"978-953-307-331-6",pdfIsbn:"978-953-51-6589-7",doi:"10.5772/1285",price:159,priceEur:175,priceUsd:205,slug:"prostate-cancer-from-bench-to-bedside",numberOfPages:530,isOpenForSubmission:!1,isInWos:1,hash:"d5a01877eb8f560e8aeee899be80f547",bookSignature:"Philippe E. Spiess",publishedDate:"November 25th 2011",coverURL:"https://cdn.intechopen.com/books/images_new/777.jpg",numberOfDownloads:41035,numberOfWosCitations:16,numberOfCrossrefCitations:7,numberOfDimensionsCitations:24,hasAltmetrics:0,numberOfTotalCitations:47,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"January 20th 2011",dateEndSecondStepPublish:"February 17th 2011",dateEndThirdStepPublish:"June 24th 2011",dateEndFourthStepPublish:"July 24th 2011",dateEndFifthStepPublish:"November 21st 2011",currentStepOfPublishingProcess:5,indexedIn:"1,2,3,4,5,6",editedByType:"Edited by",kuFlag:!1,editors:[{id:"64476",title:"Dr.",name:"Philippe E.",middleName:null,surname:"Spiess",slug:"philippe-e.-spiess",fullName:"Philippe E. Spiess",profilePictureURL:"https://mts.intechopen.com/storage/users/64476/images/1906_n.jpg",biography:"Dr Philippe E. Spiess is an assistant professor with dual appointment in the department of Genitourinary Oncology at the Moffitt Cancer Center and the department of Urology at the University of South Florida in Tampa, Florida. Dr Spiess was born and raised in Montreal, Canada where he completed his urological training at McGill University. He subsequently completed his urologic oncologic training at the M. D. Anderson Cancer Center in Houston, Texas. Dr Spiess has published over 80 peer reviewed scientific papers in urologic oncology in addition to being a nationally and internationally recognized expert in the management of genitourinary malignancies. He has dedicated much of his research efforts to optimizing the surgical management of locally advanced and locally recurrent prostate cancer. He currently sits on the NCCN Panel for bladder and penile cancer in addition to being the video section editor of the International Brazilian Journal of Urology.",institutionString:null,position:null,outsideEditionCount:0,totalCites:0,totalAuthoredChapters:"1",totalChapterViews:"0",totalEditedBooks:"3",institution:{name:"Moffitt Cancer Center",institutionURL:null,country:{name:"United States of America"}}}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,coeditorOne:null,coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"1072",title:"Anaplastology",slug:"anaplastology"}],chapters:[{id:"24217",title:"Prostate Cancer: Essential Diagnostic and Therapeutic Considerations",doi:"10.5772/33935",slug:"prostate-cancer-essential-diagnostic-and-therapeutic-considerations",totalDownloads:1064,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Paul Bradley and Philippe E. Spiess",downloadPdfUrl:"/chapter/pdf-download/24217",previewPdfUrl:"/chapter/pdf-preview/24217",authors:[{id:"64476",title:"Dr.",name:"Philippe E.",surname:"Spiess",slug:"philippe-e.-spiess",fullName:"Philippe E. Spiess"},{id:"98401",title:"Dr.",name:"Paul",surname:"Bradley",slug:"paul-bradley",fullName:"Paul Bradley"}],corrections:null},{id:"24218",title:"Effective Methodologies for Statistical Inference on Microarray Studies",doi:"10.5772/25607",slug:"effective-methodologies-for-statistical-inference-on-microarray-studies",totalDownloads:1195,totalCrossrefCites:2,totalDimensionsCites:3,signatures:"Makoto Aoshima and Kazuyoshi Yata",downloadPdfUrl:"/chapter/pdf-download/24218",previewPdfUrl:"/chapter/pdf-preview/24218",authors:[{id:"63901",title:"Prof.",name:"Makoto",surname:"Aoshima",slug:"makoto-aoshima",fullName:"Makoto Aoshima"},{id:"69218",title:"Dr.",name:"Kazuyoshi",surname:"Yata",slug:"kazuyoshi-yata",fullName:"Kazuyoshi Yata"}],corrections:null},{id:"24219",title:"Prostate Cancer, the Long Search for Etiologic and Therapeutic Factors: Dietary Supplementation Avoiding Invasive Treatment",doi:"10.5772/26134",slug:"prostate-cancer-the-long-search-for-etiologic-and-therapeutic-factors-dietary-supplementation-avoidi",totalDownloads:1433,totalCrossrefCites:1,totalDimensionsCites:1,signatures:"Thomas Tallberg and Faik Atroshi",downloadPdfUrl:"/chapter/pdf-download/24219",previewPdfUrl:"/chapter/pdf-preview/24219",authors:[{id:"65639",title:"Dr.",name:"Faik",surname:"Atroshi",slug:"faik-atroshi",fullName:"Faik Atroshi"}],corrections:null},{id:"24220",title:"Advanced Models for Target Validation & Drug Discovery in Prostate Cancer",doi:"10.5772/25629",slug:"advanced-models-for-target-validation-drug-discovery-in-prostate-cancer",totalDownloads:1870,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"Malin Åkerfelt, Ville Härmä and Matthias Nees",downloadPdfUrl:"/chapter/pdf-download/24220",previewPdfUrl:"/chapter/pdf-preview/24220",authors:[{id:"63947",title:"Dr.",name:"Matthias",surname:"Nees",slug:"matthias-nees",fullName:"Matthias Nees"},{id:"123168",title:"Dr.",name:"Malin",surname:"Åkerfelt",slug:"malin-akerfelt",fullName:"Malin Åkerfelt"},{id:"123174",title:"MSc.",name:"Ville",surname:"Härmä",slug:"ville-harma",fullName:"Ville Härmä"}],corrections:null},{id:"24221",title:"Signalling Pathways and Gene Expression Profiles in Prostate Cancer",doi:"10.5772/26971",slug:"signalling-pathways-and-gene-expression-profiles-in-prostate-cancer",totalDownloads:1543,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Sophia Marsella-Hatziieremia, Pamela McCall and Joanne Edwards",downloadPdfUrl:"/chapter/pdf-download/24221",previewPdfUrl:"/chapter/pdf-preview/24221",authors:[{id:"68439",title:"Dr.",name:"Joanne",surname:"Edwards",slug:"joanne-edwards",fullName:"Joanne Edwards"},{id:"68533",title:"Dr.",name:"Sophia",surname:"Marsella- Hatziieremia",slug:"sophia-marsella-hatziieremia",fullName:"Sophia Marsella- Hatziieremia"}],corrections:null},{id:"24222",title:"Clinical Relevance of Circulating Nucleic Acids in Blood of Prostate Cancer Patients",doi:"10.5772/25760",slug:"clinical-relevance-of-circulating-nucleic-acids-in-blood-of-prostate-cancer-patients",totalDownloads:1720,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Heidi Schwarzenbach",downloadPdfUrl:"/chapter/pdf-download/24222",previewPdfUrl:"/chapter/pdf-preview/24222",authors:[{id:"64451",title:"Dr.",name:"Heidi",surname:"Schwarzenbach",slug:"heidi-schwarzenbach",fullName:"Heidi Schwarzenbach"}],corrections:null},{id:"24223",title:"TRP-Channels and Human Prostate Carcinogenesis",doi:"10.5772/28748",slug:"trp-channels-and-human-prostate-carcinogenesis",totalDownloads:1408,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"V’yacheslav Lehen’kyi and Natalia Prevarskaya",downloadPdfUrl:"/chapter/pdf-download/24223",previewPdfUrl:"/chapter/pdf-preview/24223",authors:[{id:"75212",title:"Dr.",name:"V'Yacheslav",surname:"Lehen'Kyi",slug:"v'yacheslav-lehen'kyi",fullName:"V'Yacheslav Lehen'Kyi"},{id:"119798",title:"Prof.",name:"Natalia",surname:"Prevarskaya",slug:"natalia-prevarskaya",fullName:"Natalia Prevarskaya"}],corrections:null},{id:"24224",title:"Epidermal Growth Factor Receptor (EGFR) Phosphorylation, Signaling and Trafficking in Prostate Cancer",doi:"10.5772/27021",slug:"epidermal-growth-factor-receptor-egfr-phosphorylation-signaling-and-trafficking-in-prostate-cancer",totalDownloads:5077,totalCrossrefCites:1,totalDimensionsCites:7,signatures:"Yao Huang and Yongchang Chang",downloadPdfUrl:"/chapter/pdf-download/24224",previewPdfUrl:"/chapter/pdf-preview/24224",authors:[{id:"68588",title:"Dr.",name:"Yao",surname:"Huang",slug:"yao-huang",fullName:"Yao Huang"},{id:"117341",title:"Dr.",name:"Yongchang",surname:"Chang",slug:"yongchang-chang",fullName:"Yongchang Chang"}],corrections:null},{id:"24225",title:"Prostate Cancer Dephosphorylation Atlas",doi:"10.5772/26158",slug:"prostate-cancer-dephosphorylation-atlas",totalDownloads:1551,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Carmen Veríssima Ferreira, Renato Milani, Willian Fernando Zambuzzi, Thomas Martin Halder, Eduardo Galembeck and Hiroshi Aoyama",downloadPdfUrl:"/chapter/pdf-download/24225",previewPdfUrl:"/chapter/pdf-preview/24225",authors:[{id:"61709",title:"Prof.",name:"Carmen",surname:"Ferreira",slug:"carmen-ferreira",fullName:"Carmen Ferreira"},{id:"70172",title:"Prof.",name:"Hiroshi",surname:"Aoyama",slug:"hiroshi-aoyama",fullName:"Hiroshi Aoyama"},{id:"70173",title:"Prof.",name:"Eduardo",surname:"Galembeck",slug:"eduardo-galembeck",fullName:"Eduardo Galembeck"},{id:"70175",title:"Prof.",name:"Willian",surname:"Zambuzzi",slug:"willian-zambuzzi",fullName:"Willian Zambuzzi"},{id:"70177",title:"Dr.",name:"Thomas",surname:"Halder",slug:"thomas-halder",fullName:"Thomas Halder"},{id:"70179",title:"MSc",name:"Renato",surname:"Milani",slug:"renato-milani",fullName:"Renato Milani"}],corrections:null},{id:"24226",title:"Modulation of One-Carbon Metabolism by B Vitamins: Implications for Transformation and Progression of Prostate Cancer",doi:"10.5772/25307",slug:"modulation-of-one-carbon-metabolism-by-b-vitamins-implications-for-transformation-and-progression-of",totalDownloads:2200,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"Glenn Tisman",downloadPdfUrl:"/chapter/pdf-download/24226",previewPdfUrl:"/chapter/pdf-preview/24226",authors:[{id:"62945",title:"Dr.",name:"Glenn",surname:"Tisman",slug:"glenn-tisman",fullName:"Glenn Tisman"}],corrections:null},{id:"24227",title:"Integrins as Determinants of Genetic Susceptibility, Tumour Behaviour and Their Potential as Therapeutic Targets",doi:"10.5772/25358",slug:"integrins-as-determinants-of-genetic-susceptibility-tumour-behaviour-and-their-potential-as-therapeu",totalDownloads:1376,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"James R. Marthick, Adele F. Holloway and Joanne L. Dickinson",downloadPdfUrl:"/chapter/pdf-download/24227",previewPdfUrl:"/chapter/pdf-preview/24227",authors:[{id:"63081",title:"Dr.",name:"Joanne",surname:"Dickinson",slug:"joanne-dickinson",fullName:"Joanne Dickinson"},{id:"70194",title:"Mr",name:"James",surname:"Marthick",slug:"james-marthick",fullName:"James Marthick"},{id:"70199",title:"Dr.",name:"Adele",surname:"Holloway",slug:"adele-holloway",fullName:"Adele Holloway"}],corrections:null},{id:"24228",title:"Cytotoxic Endonucleases: New Targets for Prostate Cancer Chemotherapy",doi:"10.5772/25585",slug:"cytotoxic-endonucleases-new-targets-for-prostate-cancer-chemotherapy",totalDownloads:1608,totalCrossrefCites:1,totalDimensionsCites:1,signatures:"Xiaoying Wang, Marina V. Mikhailova and Alexei G. Basnakian",downloadPdfUrl:"/chapter/pdf-download/24228",previewPdfUrl:"/chapter/pdf-preview/24228",authors:[{id:"63828",title:"Dr.",name:"Alexei",surname:"Basnakian",slug:"alexei-basnakian",fullName:"Alexei Basnakian"},{id:"69445",title:"Dr.",name:"Marina",surname:"Mikhailova",slug:"marina-mikhailova",fullName:"Marina Mikhailova"},{id:"69446",title:"Dr.",name:"Xiaoying",surname:"Wang",slug:"xiaoying-wang",fullName:"Xiaoying Wang"}],corrections:null},{id:"24229",title:"MAP Kinases and Prostate Cancer",doi:"10.5772/25989",slug:"map-kinases-and-prostate-cancer",totalDownloads:1527,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Gonzalo Rodríguez-Berriguete, Benito Fraile, Laura Galvis, Ricardo Paniagua and Mar Royuela",downloadPdfUrl:"/chapter/pdf-download/24229",previewPdfUrl:"/chapter/pdf-preview/24229",authors:[{id:"65198",title:"Prof.",name:"Mar",surname:"Royuela",slug:"mar-royuela",fullName:"Mar Royuela"}],corrections:null},{id:"24230",title:"Evaluation of Phyllanthus, for Its Anti-Cancer Properties",doi:"10.5772/27296",slug:"evaluation-of-phyllanthus-for-its-anti-cancer-properties",totalDownloads:3285,totalCrossrefCites:1,totalDimensionsCites:5,signatures:"Yin-Quan Tang and Shamala Devi Sekaran",downloadPdfUrl:"/chapter/pdf-download/24230",previewPdfUrl:"/chapter/pdf-preview/24230",authors:[{id:"69612",title:"Prof.",name:"Shamala Devi",surname:"Sekaran",slug:"shamala-devi-sekaran",fullName:"Shamala Devi Sekaran"},{id:"69617",title:"Dr.",name:"Yin Quan",surname:"Tang",slug:"yin-quan-tang",fullName:"Yin Quan Tang"}],corrections:null},{id:"24231",title:"Prostate Cancer Progression to Androgen Independent Disease: The Role of the Wnt/β-Catenin Pathway",doi:"10.5772/26201",slug:"prostate-cancer-progression-to-androgen-independent-disease-the-role-of-the-wnt-catenin-pathway",totalDownloads:1542,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Jacqueline R. Ha, Yu Hao D. Huang and Sujata Persad",downloadPdfUrl:"/chapter/pdf-download/24231",previewPdfUrl:"/chapter/pdf-preview/24231",authors:[{id:"65838",title:"Dr.",name:"Sujata",surname:"Persad",slug:"sujata-persad",fullName:"Sujata Persad"},{id:"69936",title:"MSc.",name:"Jacqueline R",surname:"Ha",slug:"jacqueline-r-ha",fullName:"Jacqueline R Ha"},{id:"121836",title:"B.Sc.",name:"YuHao",surname:"Huang",slug:"yuhao-huang",fullName:"YuHao Huang"}],corrections:null},{id:"24232",title:"Prostate Carcinoma and Hot Flashes",doi:"10.5772/26303",slug:"prostate-carcinoma-and-hot-flashes",totalDownloads:1963,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Santiago Vilar-González and Alberto Pérez-Rozos",downloadPdfUrl:"/chapter/pdf-download/24232",previewPdfUrl:"/chapter/pdf-preview/24232",authors:[{id:"66184",title:"Dr.",name:"Santiago",surname:"Vilar González",slug:"santiago-vilar-gonzalez",fullName:"Santiago Vilar González"},{id:"66328",title:"Prof.",name:"Alberto",surname:"Pérez Rozos",slug:"alberto-perez-rozos",fullName:"Alberto Pérez Rozos"}],corrections:null},{id:"24233",title:"Paradigm Shift in the Concept of Hormonal Milieu of Prostate Cancer",doi:"10.5772/25625",slug:"paradigm-shift-in-the-concept-of-hormonal-milieu-of-prostate-cancer",totalDownloads:1380,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"Tsutomu Nishiyama",downloadPdfUrl:"/chapter/pdf-download/24233",previewPdfUrl:"/chapter/pdf-preview/24233",authors:[{id:"63939",title:"Dr.",name:"Tsutomu",surname:"Nishiyama",slug:"tsutomu-nishiyama",fullName:"Tsutomu Nishiyama"}],corrections:null},{id:"24234",title:"The Role of Cancer Stem Cells and MicroRNAs in Human Prostate Cancer",doi:"10.5772/26430",slug:"the-role-of-cancer-stem-cells-and-micrornas-in-human-prostate-cancer",totalDownloads:1502,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Mustafa Ozen and Serhat Sevli",downloadPdfUrl:"/chapter/pdf-download/24234",previewPdfUrl:"/chapter/pdf-preview/24234",authors:[{id:"66575",title:"Prof.",name:"Mustafa",surname:"Ozen",slug:"mustafa-ozen",fullName:"Mustafa Ozen"},{id:"69466",title:"MSc.",name:"Serhat",surname:"Sevli",slug:"serhat-sevli",fullName:"Serhat Sevli"}],corrections:null},{id:"24235",title:"Zinc Supplementation and Prostate Cancer",doi:"10.5772/25506",slug:"zinc-supplementation-and-prostate-cancer",totalDownloads:2887,totalCrossrefCites:1,totalDimensionsCites:1,signatures:"Wong Pooi-Fong and AbuBakar Sazaly",downloadPdfUrl:"/chapter/pdf-download/24235",previewPdfUrl:"/chapter/pdf-preview/24235",authors:[{id:"63537",title:"Prof.",name:"Sazaly",surname:"AbuBakar",slug:"sazaly-abubakar",fullName:"Sazaly AbuBakar"},{id:"69055",title:"Dr.",name:"Pooi-Fong",surname:"Wong",slug:"pooi-fong-wong",fullName:"Pooi-Fong Wong"}],corrections:null},{id:"24236",title:"The Role of Vitamin D in the Prevention and Treatment of Prostate Cancer",doi:"10.5772/25312",slug:"the-role-of-vitamin-d-in-the-prevention-and-treatment-of-prostate-cancer",totalDownloads:1768,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Sophia L. Maund and Scott D. Cramer",downloadPdfUrl:"/chapter/pdf-download/24236",previewPdfUrl:"/chapter/pdf-preview/24236",authors:[{id:"62964",title:"Prof.",name:"Scott D.",surname:"Cramer",slug:"scott-d.-cramer",fullName:"Scott D. Cramer"},{id:"62965",title:"Ms",name:"Sophia L.",surname:"Maund",slug:"sophia-l.-maund",fullName:"Sophia L. Maund"}],corrections:null},{id:"24237",title:"Highlights of Natural Products in Prostate Cancer Drug Discovery",doi:"10.5772/27401",slug:"highlights-of-natural-products-in-prostate-cancer-drug-discovery",totalDownloads:1638,totalCrossrefCites:0,totalDimensionsCites:0,signatures:"Jorge A. R. Salvador and Vânia M. Moreira",downloadPdfUrl:"/chapter/pdf-download/24237",previewPdfUrl:"/chapter/pdf-preview/24237",authors:[{id:"69976",title:"Prof.",name:"Jorge António Ribeiro",surname:"Salvador",slug:"jorge-antonio-ribeiro-salvador",fullName:"Jorge António Ribeiro Salvador"},{id:"69991",title:"Dr.",name:"Vânia",surname:"Moreira",slug:"vania-moreira",fullName:"Vânia Moreira"}],corrections:null},{id:"24238",title:"The Potential Target Therapy of Prostate Cancer Stem Cells",doi:"10.5772/30062",slug:"the-potential-target-therapy-of-prostate-cancer-stem-cells",totalDownloads:1501,totalCrossrefCites:0,totalDimensionsCites:1,signatures:"Luis A. Espinoza, Christopher Albanese and Olga C. Rodriguez",downloadPdfUrl:"/chapter/pdf-download/24238",previewPdfUrl:"/chapter/pdf-preview/24238",authors:[{id:"80628",title:"Dr.",name:"Luis",surname:"Espinoza",slug:"luis-espinoza",fullName:"Luis Espinoza"},{id:"119925",title:"Dr.",name:"Chris",surname:"Albanese",slug:"chris-albanese",fullName:"Chris Albanese"},{id:"119926",title:"Dr.",name:"Olga",surname:"Rodriguez",slug:"olga-rodriguez",fullName:"Olga Rodriguez"}],corrections:null}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},relatedBooks:[{type:"book",id:"1845",title:"Prostate Cancer",subtitle:"Diagnostic and Therapeutic Advances",isOpenForSubmission:!1,hash:"3be3f6b756cec080cfcacd2251b62a5c",slug:"prostate-cancer-diagnostic-and-therapeutic-advances",bookSignature:"Philippe E. Spiess",coverURL:"https://cdn.intechopen.com/books/images_new/1845.jpg",editedByType:"Edited by",editors:[{id:"64476",title:"Dr.",name:"Philippe E.",surname:"Spiess",slug:"philippe-e.-spiess",fullName:"Philippe E. Spiess"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1985",title:"Prostate Cancer",subtitle:"Original Scientific Reports and Case Studies",isOpenForSubmission:!1,hash:"51d83bcaa97cb41331a0e6cc466f237f",slug:"prostate-cancer-original-scientific-reports-and-case-studies",bookSignature:"Philippe E. Spiess",coverURL:"https://cdn.intechopen.com/books/images_new/1985.jpg",editedByType:"Edited by",editors:[{id:"64476",title:"Dr.",name:"Philippe E.",surname:"Spiess",slug:"philippe-e.-spiess",fullName:"Philippe E. Spiess"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5231",title:"Prostate Cancer",subtitle:"Leading-edge Diagnostic Procedures and Treatments",isOpenForSubmission:!1,hash:"99ab241dee1141397af0cc73d25cb2f1",slug:"prostate-cancer-leading-edge-diagnostic-procedures-and-treatments",bookSignature:"Ravinder Mohan",coverURL:"https://cdn.intechopen.com/books/images_new/5231.jpg",editedByType:"Edited by",editors:[{id:"58197",title:"Prof.",name:"Ravinder",surname:"Mohan",slug:"ravinder-mohan",fullName:"Ravinder Mohan"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1373",title:"Ionic Liquids",subtitle:"Applications and Perspectives",isOpenForSubmission:!1,hash:"5e9ae5ae9167cde4b344e499a792c41c",slug:"ionic-liquids-applications-and-perspectives",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/1373.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"57",title:"Physics and Applications of Graphene",subtitle:"Experiments",isOpenForSubmission:!1,hash:"0e6622a71cf4f02f45bfdd5691e1189a",slug:"physics-and-applications-of-graphene-experiments",bookSignature:"Sergey Mikhailov",coverURL:"https://cdn.intechopen.com/books/images_new/57.jpg",editedByType:"Edited by",editors:[{id:"16042",title:"Dr.",name:"Sergey",surname:"Mikhailov",slug:"sergey-mikhailov",fullName:"Sergey Mikhailov"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"371",title:"Abiotic Stress in Plants",subtitle:"Mechanisms and Adaptations",isOpenForSubmission:!1,hash:"588466f487e307619849d72389178a74",slug:"abiotic-stress-in-plants-mechanisms-and-adaptations",bookSignature:"Arun Shanker and B. Venkateswarlu",coverURL:"https://cdn.intechopen.com/books/images_new/371.jpg",editedByType:"Edited by",editors:[{id:"58592",title:"Dr.",name:"Arun",surname:"Shanker",slug:"arun-shanker",fullName:"Arun Shanker"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],ofsBooks:[]},correction:{item:{id:"65668",slug:"corrigendum-to-clinical-applications-of-mesenchymal-stromal-cells-mscs-in-orthopedic-diseases",title:"Corrigendum to: Clinical Applications of Mesenchymal Stromal Cells (MSCs) in Orthopedic Diseases",doi:null,correctionPDFUrl:"https://cdn.intechopen.com/pdfs/65668.pdf",downloadPdfUrl:"/chapter/pdf-download/65668",previewPdfUrl:"/chapter/pdf-preview/65668",totalDownloads:null,totalCrossrefCites:null,bibtexUrl:"/chapter/bibtex/65668",risUrl:"/chapter/ris/65668",chapter:{id:"61187",slug:"clinical-applications-of-mesenchymal-stromal-cells-mscs-in-orthopedic-diseases",signatures:"Jiazhao Yang, Shiyuan Fang, Lei Xu, Li Li, Kai Xie, Jinsen Lu, Hao\nWang, Xujin Wang and Lixin Kan",dateSubmitted:"December 5th 2017",dateReviewed:"March 29th 2018",datePrePublished:"November 5th 2018",datePublished:"January 23rd 2019",book:{id:"6658",title:"Stromal Cells",subtitle:"Structure, Function, and Therapeutic Implications",fullTitle:"Stromal Cells - Structure, Function, and Therapeutic Implications",slug:"stromal-cells-structure-function-and-therapeutic-implications",publishedDate:"January 23rd 2019",bookSignature:"Mani T. Valarmathi",coverURL:"https://cdn.intechopen.com/books/images_new/6658.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"69697",title:"Dr.",name:"Mani T.",middleName:null,surname:"Valarmathi",slug:"mani-t.-valarmathi",fullName:"Mani T. Valarmathi"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:null}},chapter:{id:"61187",slug:"clinical-applications-of-mesenchymal-stromal-cells-mscs-in-orthopedic-diseases",signatures:"Jiazhao Yang, Shiyuan Fang, Lei Xu, Li Li, Kai Xie, Jinsen Lu, Hao\nWang, Xujin Wang and Lixin Kan",dateSubmitted:"December 5th 2017",dateReviewed:"March 29th 2018",datePrePublished:"November 5th 2018",datePublished:"January 23rd 2019",book:{id:"6658",title:"Stromal Cells",subtitle:"Structure, Function, and Therapeutic Implications",fullTitle:"Stromal Cells - Structure, Function, and Therapeutic Implications",slug:"stromal-cells-structure-function-and-therapeutic-implications",publishedDate:"January 23rd 2019",bookSignature:"Mani T. Valarmathi",coverURL:"https://cdn.intechopen.com/books/images_new/6658.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"69697",title:"Dr.",name:"Mani T.",middleName:null,surname:"Valarmathi",slug:"mani-t.-valarmathi",fullName:"Mani T. Valarmathi"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}},authors:null},book:{id:"6658",title:"Stromal Cells",subtitle:"Structure, Function, and Therapeutic Implications",fullTitle:"Stromal Cells - Structure, Function, and Therapeutic Implications",slug:"stromal-cells-structure-function-and-therapeutic-implications",publishedDate:"January 23rd 2019",bookSignature:"Mani T. Valarmathi",coverURL:"https://cdn.intechopen.com/books/images_new/6658.jpg",licenceType:"CC BY 3.0",editedByType:"Edited by",editors:[{id:"69697",title:"Dr.",name:"Mani T.",middleName:null,surname:"Valarmathi",slug:"mani-t.-valarmathi",fullName:"Mani T. Valarmathi"}],productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"}}},ofsBook:{item:{type:"book",id:"10830",leadTitle:null,title:"Animal Feed Science",subtitle:null,reviewType:"peer-reviewed",abstract:"This book will be a self-contained collection of scholarly papers targeting an audience of practicing researchers, academics, PhD students and other scientists. The contents of the book will be written by multiple authors and edited by experts in the field.",isbn:null,printIsbn:null,pdfIsbn:null,doi:null,price:0,priceEur:0,priceUsd:0,slug:null,numberOfPages:0,isOpenForSubmission:!1,hash:"b6091426454b1c484f4d38efc722d6dd",bookSignature:"",publishedDate:null,coverURL:"https://cdn.intechopen.com/books/images_new/10830.jpg",keywords:null,numberOfDownloads:null,numberOfWosCitations:0,numberOfCrossrefCitations:null,numberOfDimensionsCitations:null,numberOfTotalCitations:null,isAvailableForWebshopOrdering:!0,dateEndFirstStepPublish:"November 25th 2020",dateEndSecondStepPublish:"December 16th 2020",dateEndThirdStepPublish:"February 14th 2021",dateEndFourthStepPublish:"May 5th 2021",dateEndFifthStepPublish:"July 4th 2021",remainingDaysToSecondStep:"a month",secondStepPassed:!0,currentStepOfPublishingProcess:1,editedByType:null,kuFlag:!1,biosketch:null,coeditorOneBiosketch:null,coeditorTwoBiosketch:null,coeditorThreeBiosketch:null,coeditorFourBiosketch:null,coeditorFiveBiosketch:null,editors:null,coeditorOne:null,coeditorTwo:null,coeditorThree:null,coeditorFour:null,coeditorFive:null,topics:[{id:"25",title:"Veterinary Medicine and Science",slug:"veterinary-medicine-and-science"}],chapters:null,productType:{id:"1",title:"Edited Volume",chapterContentType:"chapter",authoredCaption:"Edited by"},personalPublishingAssistant:null},relatedBooks:[{type:"book",id:"7144",title:"Veterinary Anatomy and Physiology",subtitle:null,isOpenForSubmission:!1,hash:"75cdacb570e0e6d15a5f6e69640d87c9",slug:"veterinary-anatomy-and-physiology",bookSignature:"Catrin Sian Rutland and Valentina Kubale",coverURL:"https://cdn.intechopen.com/books/images_new/7144.jpg",editedByType:"Edited by",editors:[{id:"202192",title:"Dr.",name:"Catrin",surname:"Rutland",slug:"catrin-rutland",fullName:"Catrin Rutland"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1591",title:"Infrared Spectroscopy",subtitle:"Materials Science, Engineering and Technology",isOpenForSubmission:!1,hash:"99b4b7b71a8caeb693ed762b40b017f4",slug:"infrared-spectroscopy-materials-science-engineering-and-technology",bookSignature:"Theophile Theophanides",coverURL:"https://cdn.intechopen.com/books/images_new/1591.jpg",editedByType:"Edited by",editors:[{id:"37194",title:"Dr.",name:"Theophanides",surname:"Theophile",slug:"theophanides-theophile",fullName:"Theophanides Theophile"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3092",title:"Anopheles mosquitoes",subtitle:"New insights into malaria vectors",isOpenForSubmission:!1,hash:"c9e622485316d5e296288bf24d2b0d64",slug:"anopheles-mosquitoes-new-insights-into-malaria-vectors",bookSignature:"Sylvie Manguin",coverURL:"https://cdn.intechopen.com/books/images_new/3092.jpg",editedByType:"Edited by",editors:[{id:"50017",title:"Prof.",name:"Sylvie",surname:"Manguin",slug:"sylvie-manguin",fullName:"Sylvie Manguin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"3161",title:"Frontiers in Guided Wave Optics and Optoelectronics",subtitle:null,isOpenForSubmission:!1,hash:"deb44e9c99f82bbce1083abea743146c",slug:"frontiers-in-guided-wave-optics-and-optoelectronics",bookSignature:"Bishnu Pal",coverURL:"https://cdn.intechopen.com/books/images_new/3161.jpg",editedByType:"Edited by",editors:[{id:"4782",title:"Prof.",name:"Bishnu",surname:"Pal",slug:"bishnu-pal",fullName:"Bishnu Pal"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"72",title:"Ionic Liquids",subtitle:"Theory, Properties, New Approaches",isOpenForSubmission:!1,hash:"d94ffa3cfa10505e3b1d676d46fcd3f5",slug:"ionic-liquids-theory-properties-new-approaches",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/72.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"1373",title:"Ionic Liquids",subtitle:"Applications and Perspectives",isOpenForSubmission:!1,hash:"5e9ae5ae9167cde4b344e499a792c41c",slug:"ionic-liquids-applications-and-perspectives",bookSignature:"Alexander Kokorin",coverURL:"https://cdn.intechopen.com/books/images_new/1373.jpg",editedByType:"Edited by",editors:[{id:"19816",title:"Prof.",name:"Alexander",surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"57",title:"Physics and Applications of Graphene",subtitle:"Experiments",isOpenForSubmission:!1,hash:"0e6622a71cf4f02f45bfdd5691e1189a",slug:"physics-and-applications-of-graphene-experiments",bookSignature:"Sergey Mikhailov",coverURL:"https://cdn.intechopen.com/books/images_new/57.jpg",editedByType:"Edited by",editors:[{id:"16042",title:"Dr.",name:"Sergey",surname:"Mikhailov",slug:"sergey-mikhailov",fullName:"Sergey Mikhailov"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"371",title:"Abiotic Stress in Plants",subtitle:"Mechanisms and Adaptations",isOpenForSubmission:!1,hash:"588466f487e307619849d72389178a74",slug:"abiotic-stress-in-plants-mechanisms-and-adaptations",bookSignature:"Arun Shanker and B. Venkateswarlu",coverURL:"https://cdn.intechopen.com/books/images_new/371.jpg",editedByType:"Edited by",editors:[{id:"58592",title:"Dr.",name:"Arun",surname:"Shanker",slug:"arun-shanker",fullName:"Arun Shanker"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"878",title:"Phytochemicals",subtitle:"A Global Perspective of Their Role in Nutrition and Health",isOpenForSubmission:!1,hash:"ec77671f63975ef2d16192897deb6835",slug:"phytochemicals-a-global-perspective-of-their-role-in-nutrition-and-health",bookSignature:"Venketeshwer Rao",coverURL:"https://cdn.intechopen.com/books/images_new/878.jpg",editedByType:"Edited by",editors:[{id:"82663",title:"Dr.",name:"Venketeshwer",surname:"Rao",slug:"venketeshwer-rao",fullName:"Venketeshwer Rao"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"4816",title:"Face Recognition",subtitle:null,isOpenForSubmission:!1,hash:"146063b5359146b7718ea86bad47c8eb",slug:"face_recognition",bookSignature:"Kresimir Delac and Mislav Grgic",coverURL:"https://cdn.intechopen.com/books/images_new/4816.jpg",editedByType:"Edited by",editors:[{id:"528",title:"Dr.",name:"Kresimir",surname:"Delac",slug:"kresimir-delac",fullName:"Kresimir Delac"}],productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},chapter:{item:{type:"chapter",id:"54658",title:"Organic-Inorganic Hybrid Coatings for Corrosion Protection of Metallic Surfaces",doi:"10.5772/67909",slug:"organic-inorganic-hybrid-coatings-for-corrosion-protection-of-metallic-surfaces",body:'
Since the discovery of copper in prehistoric times, an extensive diversity of metallic materials has emerged, as pure metals or metal alloys. Brass, bronze, steel, titanium, and aluminum alloys are currently the most applied metallic materials, notwithstanding the natural tendency to suffer corrosion under aggressive conditions and thus return to their original ore. To overcome issues related with economical losses and lack of safety, occasioned by metal corrosion, several protection methods have been developed, including the use of:
new alloys with higher corrosion resistance, but in addition to the high cost associated with their development, the use of new alloys requires the replacement of the metallic components;
corrosion inhibitors, substances which reduce or even eliminate corrosion, when present in suitable concentrations in the corrosive medium. Inhibition is accomplished by one or a combination of several mechanisms, such as adsorption, forming a ultrathin film with a thickness of only few molecular layers; in form of visible bulky precipitates, which coat the metal surface; or other common methods consisting of the combination of adsorption, conversion, and oxidation processes to form a passive layer. Some examples of most applied inhibitors are phosphates, chromates, silicates, hydroxides, carbonates, sulfates, aldehydes, amines, nitrogen heterocyclic compounds, urea, among others [1];
cathodic protection that uses a sacrificial metal to protect the metallic structure of interest. It is commonly used to prevent corrosion in large port structures, offshore platforms, and pipelines to transport water, oil, and gas;
conversion layer produced by converting the metal surface into a corrosion-resistant form. The main processes include anodizing, phosphatizing, and chromating, and they are frequently used as pretreatment for subsequent overcoats [1]. Anodizing is based on the formation of a protective surface layer, formed by oxides and hydroxides, by application of an external current. In an electrochemical cell, the surface of the metal anode is transformed into an oxide layer of defined thickness, which improves significantly the corrosion resistance and the adhesion of subsequent paints. This method is frequently applied to protect aluminum alloys but can be used also for titanium, zinc, magnesium, and other metal substrates. Besides the presence of microscopic fissures in the anodizing coating that can lead to corrosion, another drawback is the susceptibility of the oxide layer to chemical dissolution in the presence of high- and low-pH environments. Phosphatizing is mostly applied on steel substrates to produce an insoluble and porous phosphate layer that serves as an excellent base for coatings. For instance, car bodies have been phosphatized prior to the application of coatings for many years [1]. Alternatively, surface passivation using chromate conversion coatings has been used especially to protect aluminum alloys in the aerospace industry, for metal fittings and for packaging steel [2, 3]. Such coatings are formed by the reduction of Cr(VI) species to hydrated Cr2O3; however, the conversion process as well as the final coating retains a small amount of unreacted Cr(VI), a highly toxic species which can be released to the environment. Recently, increasing efforts are focused on the development of innovative eco-friendly alternatives due to increasingly strict legislation regulations which demand a reduction of hexavalent chromates usage [3];
protective coatings applied on metal surfaces result in a barrier between the metal and the corrosive medium, thus preventing or minimizing the corrosion process.
The use of coatings on metallic surfaces has various advantages, such as relatively low costs, environmental compatibility, and the possibility to apply them on metallic components already in use. Consequently, different kinds of protective coatings have been developed, comprising metallic, inorganic, organic, or organic-inorganic materials. The application of many metal coatings, such as chromium, zinc, nickel, aluminum, and copper, involves usually inherent pollution and toxicity-related problems. The most widely used metallic coating is zinc, commonly deposited on carbon steel by hot-dip on a molten zinc bath, process called galvanization, after which the metal substrate acquires a zinc-rich top layer with a thickness of approximately 10 μm. Inorganic coatings comprise ceramics (silica, titania, zirconia, alumina), glass, carbon, etc [1]. Although the inorganic coatings present higher corrosion resistance compared to bare substrates, they usually exhibit residual porosity and stress-induced cracks, which limit their use as efficient corrosion barrier as they allow the diffusion of corrosive species to the underlying metal [4, 5]. Organic materials such as epoxy, poly(methyl methacrylate) (PMMA), polyurethane (PU), polyesters, fluoropolymers, and related paints, combined with anticorrosive primer containing various types of pigments, are widely applied as protective coatings. This is justified by the simplicity of deposition, their dense and homogeneous structure, and consequently high corrosion resistance in aggressive environments. However, their lack of thermal stability, mechanical resistance and adhesion to metallic surfaces can result in serious restriction of their long-term stability.
Organic-inorganic hybrids stand for a class of materials formed by the combination of a polymeric and a ceramic phase, resulting in a nanocomposite material with unique properties. New functionalities result from the synergy of both components, achieved by a careful adjustment of the nature, proportion, and the type of interaction at the interface of both phases. One of the most used methodologies to produce organic-inorganic hybrid materials is the sol-gel process, which allows due to its versatility to control the structure and the functional properties. Through hydrolysis and condensations reactions, the sol-gel route allows the obtain high purity, homogeneous, and structurally tuneable materials, which have a wide range of applications such as catalysts, drug release systems, photochromic devices, biosensors, transparent insulating films, and anticorrosive coatings with excellent barrier properties [6]. The latter characteristic is related to the possibility to prepare a dense organic-inorganic network structure by linking both phases covalently on the molecular scale, and furthermore, the ability to covalently bond the inorganic phase with metallic substrates, leading to highly adherent coatings. Consequently, intense research efforts are presently focused on the development of organic-inorganic hybrid coatings in form of passive barrier layers with low permeability for corrosive species such as chloride ions, water, and oxygen.
There are various methodologies to investigate the corrosion protection efficiency of coated metals; however, the most applied electrochemical techniques are electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and chronopotentiometry. Among them, EIS allows for a deeper analysis of the electrolyte/coating/substrate systems, due to the possibility to fit the data using equivalent electrical circuits, which permit to extract important electrochemical parameters such as coating capacitance, pore resistance, double layer capacitance, charge transfer resistance, water uptake, diffusivity, among others. Additional methods like salt spray test and immersion techniques are used according to different norms for the qualitative and quantitative evaluation of corrosion zones, pitting, and for the determination of corrosion rates. To evaluate the electrochemical performance of the protective system for a given corrosive environment and coating thickness, the most important criteria are (i) the magnitude of the initial impedance modulus obtained by EIS at low frequency, defined as corrosion resistance; (ii) the values of the open circuit potential, obtained by chronopotentiometry; and (iii) the time evolution of both parameters, to evaluate the long-term stability of the coatings. For industrial application, another important aspects have to be considered such as the simplicity of the synthesis process, low costs of reagents, and their environmental compatibility.
One example of an efficient corrosion protection of mild steel was recently reported for a hybrid system combining an epoxy-siloxane topcoat with an epoxy primer containing micaceous iron oxide and zinc phosphate pigments [7]. The electrochemical measurements showed a high-impedance modulus of up to 100 GΩ cm2, remaining stable for more than 1 year in contact with 3% NaCl solution. The authors attribute the excellent protection to the high resistance of the coating against water uptake provided by suitable epoxy/primer combination and the relatively high thickness (~140 μm) of this coating system. In another recent study, Ammar et al. [8] report on high-performance hybrid coatings based on acrylic-silica polymeric matrix reinforced by SiO2 nanoparticles, applied to mild steel with a thickness of 75 μm by brush coating. EIS measurements confirmed the high-corrosion protection efficiency with an impedance modulus of more than 10 GΩ cm2, decreasing one decade after 90 days of immersion in 3.5% NaCl solution. Visuet et al. [9] obtained similar results for polyurethane/polysiloxane hybrid coatings containing TiO2 as pigment. The EIS analysis showed that coatings loaded with 10-wt% TiO2 (75 μm thick) were able to withstand 263 days, in 3.5% NaCl solution, with almost unaltered corrosion resistance of about 100 GΩ cm2. Their model proposes that the TiO2 pigment works as a charge (ionic) storage surfaces, thus enhancing the barrier property of the coating against electrolyte uptake.
The above results demonstrate that elevated anticorrosive performance is usually achieved for sophisticated barrier coatings with an average thickness in the order of dozens to hundreds micrometers. For the market, however, which aims on economic and efficient solutions, elevated thickness, and complexity of the coating system, implies elevated material costs and weight increase, issues that are hardly to be accepted, especially by the aerospace industry. In this regard, dos Santos and coauthors [10] have successfully prepared highly efficient PMMA-silica coatings having a thickness of only ~2 μm, which were able to withstand aggressive saline/acid (0.05 mol L−1 NaCl + 0.05 mol L−1 H2SO4) and 3.5% NaCl environments for up to 105 and 196 days, respectively, maintaining the corrosion resistance in the GΩ cm2 range. The excellent performance of the primer free coating was explained by the high connectivity of reticulated sub-nanometric silica domains densely interconnected by short PMMA chain segments. Another results that confirmed the viability of thin hybrid films as efficient corrosion barrier have been reported in the study of Harb et al. [11]. The authors showed that the addition of cerium (IV) salt into PMMA-silica system results in a further improvement of the corrosion resistance and durability of the coatings applied to polished carbon steel by dip-coating. The electrochemical behavior of ~1.5 μm thick films reached for a Ce/Si molar ratio of 0.7% an impedance modulus of about 10 GΩ cm2 (NaCl 3.5% solution) and remained stable within one order of magnitude for 304 days, a performance typically observed for high performance paint systems. The remarkable anticorrosive protection has been associated with the role of Ce(IV) as oxidation agent leading to an enhancement of the overall connectivity of the hybrid network, induced by the enhanced polymerization of organic and inorganic moieties.
In contrast to coating system designed as passive barrier, recent trends aim on the development of active multifunctional anticorrosive coatings with self-healing ability, high-thermal stability, and mechanical resistance, among other functionalities. Inspired by biological systems, the self-healing ability involves the complete recovery of the original properties of the material after suffering macroscopic lesions, induced by mechanical or chemical processes. Various strategies have been used to prepare self-healing coatings, usually containing an active compound, whether stored in microcapsules or incorporated into the coating. They can be activated by temperature increase, UV, pH gradient, breaking of capsules, or changes in the chemical environment [12, 13]. A number of studies report on the use of cerium salts (chloride and nitrates) and ceria nanoparticles as inhibitors, preventing corrosion by the self-healing ability in affected areas of inorganic, organic, and hybrid coatings. The resulting substantial lifetime increase is attributed to the formation of insoluble oxides and hydroxides in the corroded zones [3, 11, 14–17]. On the other hand, significant improvements of thermal and mechanical properties have been achieved by incorporation of clays, lignin, carbon nanotubes, graphene oxide, and graphene into polymeric or organic-inorganic matrices [18–20].
This chapter reports on recent results obtained for high-performance PMMA-silica and epoxy-silica hybrids coatings, correlating their structural properties with the corrosion protection efficiency, accessed by potentiodynamic polarization and electrochemical impedance spectroscopy. Moreover, several interesting finding are presented regarding PMMA-silica hybrids reinforced with lignin, carbon nanotubes, and graphene oxide to improve their thermal and mechanical properties, as well as some recent results on active corrosion inhibition by the self-healing ability of Ce(IV) containing PMMA-silica coatings.
All reagents used to epoxy-silica and PMMA-silica hybrids synthesis were purchased from Sigma-Aldrich and used as received, apart from the methyl methacrylate (MMA) monomer, which had been distilled before use to remove the polymerization inhibitor. The molecular structures of the epoxy-silica and PMMA-silica hybrid precursors are presented in Figures 1 and 2, respectively, and the synthesis procedures are summarized in Figure 3.
Molecular structures of the epoxy-silica hybrid precursors.
Molecular structures of the PMMA-silica hybrid precursors.
Synthesis procedures used to prepare epoxy-silica and PMMA-silica hybrids.
Epoxy-silica hybrids were prepared from the curing reaction of poly(bisphenol A-co-epichlorohydrin), glycidyl end-capped (DGEBA, Mn = 377 g/mol) with diethyltriamine (DETA) as hardener, and (3-glycidoxypropyl)methyltriethoxysilane (GPTMS), as coupling agent between the organic and inorganic phase, combined with the sol-gel hydrolysis and condensation reactions of tetraethoxysilane (TEOS) and GPTMS. In the first step, DGEBA and GPTMS were mixed with DETA in tetrahydrofuran (THF) solvent during 4 h at 70°C and 25 min at 25°C, under constant stirring in a reflux flask. In the next step, TEOS, ethanol, and acidified water (pH 1 using nitric acid) were added to the reflux system at room temperature and stirred for an additional 1 h. At this stage, the sol-gel reactions take place, as shown below, where the alkoxide precursors (TEOS and GPTMS) are hydrolyzed, forming Si–OH groups, Eq. (1), which subsequently condense with an initial alkoxide molecule, Eq. (2), or another Si–OH group, Eq. (3), yielding Si–O–Si bond and eliminating alcohol or water, respectively. The homogeneous and transparent sols were used for the film deposition by dip-coating onto A1020 carbon steel.
Two series of epoxy-silica hybrids were prepared, varying the amount of GPTMS or TEOS and keeping the molar concentrations of other compounds constant (Figure 4). In order to ensure a fully cured thermosetting, DETA was added in a proportion that resulted in one oxirane group for each hydrogen atom of the amine groups.
Epoxy-silica hybrids sample names and compositions.
PMMA-silica hybrids have been prepared by the radical polymerization of methyl methacrylate (MMA) and 3-(trimethoxysilyl)propyl methacrylate (MPTS, also known as TMSM) using benzoyl peroxide (BPO), as thermal initiator of the polymerization, and tetrahydrofuran (THF) as solvent. The sol-gel route has been used to perform the hydrolytic condensation of tetraethoxysilane (TEOS) and MPTS, using ethanol and acidified water (pH 1 using nitric acid), during 1 h at room temperature. In the presence of acidified water, alkoxide precursors (TEOS and MPTS) are hydrolyzed and subsequently condensed to form Si–O–Si bonds. After mixing the organic and inorganic precursor, the obtained transparent and homogeneous sols were used to deposit few micrometer thick films onto A1020 carbon steel or AA2024 aluminum alloy substrates.
To investigate the relation between structure and barrier properties, the hybrids films were prepared at different synthesis conditions (Table 1), varying the ratio between the organic to inorganic phase (MMA/TEOS), the temperature (80–100°C) and time (2–4 h) of the organic precursor reaction, as well as the BPO/MMA molar ratio (0.01–0.1). The molar ratios of H2O/Si = 3.5 and ethanol/H2O = 0.5 were kept constant. Ce(IV) salt (ammonium cerium nitrate), lignin, carbon nanotube (CNT), and graphene oxide (GO) were added separately as modifier to the inorganic precursor of the PMMA-silica hybrid.
Samples | MMA:MPTS:TEOS molar ratio | BPO/MMA molar ratio | Organic phase synthesis | Filler | Reference |
---|---|---|---|---|---|
M2 | 2:1:2 | 0.01 | 70°C/2 h | – | [22] |
M4 | 4:1:2 | 0.01 | 70°C/2 h | – | [22] |
M8 | 8:1:2 | 0.01 | 70°C/2 h | – | [22] |
M10 | 10:1:2 | 0.01 | 70°C/2 h | – | [22] |
M8_4h | 8:1:2 | 0.01 | 80°C/4 h | – | [18] |
M8_4h_E0.2 | 8:1:2 | 0.01 | 80°C/4 h | [10] | |
M8_T80B0.01 | 8:1:2 | 0.01 | 80°C/4 h | – | – |
M8_T90 | 8:1:2 | 0.01 | 90°C/4 h | – | – |
M8_T100 | 8:1:2 | 0.01 | 100°C/4 h | – | – |
M8_B0.05 | 8:1:2 | 0.05 | 80°C/4 h | – | – |
M8_B0.10 | 8:1:2 | 0.10 | 80°C/4 h | – | – |
M8_Ce | 8:1:2 | 0.01 | 70°C/2 h | Ce/Si molar ratio: 0.1, 0.2, 0.3, 0.5, 0.7, 1, 3, 5% | [11] |
M8_lignin | 8:1:2 | 0.01 | 70°C/2 h | lignin: 0.05, 0.10, 0.50, 1.00 wt.% | [20] |
M8_CNT | 8:1:2 | 0.01 and 0.05 | 80°C/4 h | CCNT/Si molar ratio: 0.05% | [18] |
M8_GO | 8:1:2 | 0.01 and 0.05 | 80°C/4 h | CGO/Si molar ratio: 0.05% | [18] |
PMMA-silica hybrid preparation conditions.
Carbon steel 1020 (25 mm × 20 mm × 5 mm), a ferrous alloy with low carbon content, and 2024 aluminum alloy (20 mm × 20 mm × 1 mm) have been used as substrates. Low-carbon steels are produced in large quantities at relatively low costs and widely used in automobilist, construction, oil industries, etc [21]. Although the use of ferrous alloys is economically viable due to the low cost and versatility, corrosion is the great obstacle when it comes to the durability of these materials that undergo severe corrosion in contact with humid environments, low amounts of chloride ions and acid solutions in general. The 2000 and 7000 series of aluminum alloys, containing roughly 4.3–4.5% copper, 0.5–0.6% manganese, 1.3–1.5% magnesium, are widely used in the aerospace industry due to their improved mechanical properties; however, they are susceptible to enhanced corrosion especially at the grain boundaries. Prior to deposition, all substrates had been sanded with 100, 300, 600, and 1500 grit emery paper, washed with isopropanol for 10 min in an ultrasound bath and dried under a nitrogen stream. The deposition of the hybrids coatings was performed by dip-coating (Microchemistry—MQCTL2000MP) at a rate of 14 cm min−1, with 1 min of immersion and air-drying during 10 min at room temperature. This procedure was performed three times for each sample. The coated substrates and the remaining solution, placed in Teflon holders, were cured for 24 h at 60°C and then 3 h at 160°C to ensure the liberation of all volatile species and the densification of the hybrid matrix.
Structural and morphological characteristics have been investigated using nuclear magnetic resonance spectroscopy (NMR), X-ray photoelectron spectroscopy (XPS), small angle X-ray scattering (SAXS), atomic force microscopy (AFM) and thermogravimetric analysis (TGA). The anticorrosive properties of coated samples were evaluated by exposure of the coated samples to standard 3.5% saline and saline/acid solutions, using electrochemical impedance spectroscopy (EIS).
The thickness of the coatings was determined using a Filmetrics F3-CS optical interference system. An Agilent Technologies Model 5500 atomic force microscope was used to obtain AFM topography images, in tapping mode, with 1 × 1 μm, of the hybrid coatings deposited on the metallic substrates. 29Si nuclear magnetic resonance spectroscopy (29Si-NMR) measurements of the hybrid powders were performed in a 300-MHz Varian Inova spectrometer, using a Larmor frequency of 59.59 Hz and tetramethyl silane (TMS) as an external standard. The CasaXPS processing software was used for spectral deconvolution using Gauss profiles. XPS was carried out in a UNI-SPECS UHV surface analysis system, using the Mg Kα radiation (hν = 1253.6 eV) and pass energy of 10 eV to record the high-resolution spectra. The near surface composition was determined from relative peak intensities of carbon (C 1s), oxygen (O 1s) and silicon (Si 2p) corrected by Scofield’s atomic sensitivity factor of the corresponding elements. To study the oxidation state of Ce (Ce 3d) and the local bonding structure of carbon (C 1s), oxygen (O 1s), and silicon (Si 2p) of the coatings, the spectra were deconvoluted applying Voigt profiles and Shirley’s background subtraction using the CasaXPS software. SAXS experiments were carried out at the SAXS-1 beamline in the National Synchrotron Light Laboratory (LNLS, Campinas, Brazil) to determine the nanostructural characteristics of the hybrids. The scattering intensity I(q) was recorded as a function of the modulus of the scattering wave vector q = (4π/λ) sin θ, θ being half of the scattering angle. The SAXS beamline uses a monochromatic X-ray beam (λ = 1.548 Å) and a 2D detector, Dectris Pilatus 300k, positioned 0.9 m away from the sample holder. Thermogravimetric analysis of unsupported hybrids films was performed in a TA Instruments STD Q600 analyzer, under a nitrogen flow of 100 mL min−1.
The anticorrosive performance of hybrid coatings, deposited on A1020 carbon steel or Al2024 aluminum alloy, was investigated by electrochemical impedance spectroscopy (EIS) with a Gamry Potentiostat Reference 600, using 10 points per decade and RMS amplitude of 10 mV in a frequency range of 50 mHz–100 kHz. The electrochemical cell consisted of an Ag|AgCl|KClsat reference electrode, a platinum mesh counter electrode, a platinum electrode connected to the reference electrode through a 0.1-μF capacitor and the working electrode of either coated or uncoated metal substrate. The measurements were performed once a week, in saline (3.5% NaCl) or saline/acid solutions (0.05-mol L−1 H2SO4 + 0.05-mol L−1 NaCl), until a significant drop of the impedance modulus was observed, indicating the failure of the coating.
A number of interesting results have been obtained for novel epoxy-silica and PMMA-silica hybrid coatings, concerning their nanostructural properties, modified by the variation of synthesis conditions or by addition of nanofillers, in form of lignin, carbon nanotubes, and graphene oxide. The main purpose of this work was to relate these properties with the barrier characteristics, in terms of corrosion resistance and durability in aggressive environments and to compare the obtained results with those reported for a variety of hybrid coating systems. For the fine tuning of the performance of both coating systems toward an efficient and stable anticorrosive barrier, it is crucial to obtain detailed information on the formation process of the hybrid network and the structural and compositional properties of the nanocomposites.
Bisphenol stands for a group of chemical compounds with two hydroxyphenyl functionalities. There is a wide diversity of bisphenol molecules; however, the most common are the Bisphenol A (BPA) and the Bisphenol F (BPF) (Figure 5). Epoxy resins can be produced from the combination of bisphenol, such as bisphenol A, with epichlorohydrin (IUPAC name: 2-(chloromethyl)oxirane)) to give, for example, bisphenol A diglycidyl ether (Figure 6). The epoxy resins present in general poor thermal, mechanical, and chemical stability, properties which are however significantly improved when a curing agent is added. Most curing agents are composed of nitrogen-containing molecules that have a functionality equal or superior of three (f ≥ 3), which provides cross-linking between the bisphenol segments. The functionality is the number of available bonding sites, such as f = 4 for diamino diphenyl methane (4 hydrogens prone to provide bond), f = 6 for triethylene tetraamine, and f = 5 for diethylenetriamine (Figure 7). Curing reactions by DETA proceed by SN2 nucleophilic attack of the curing agent to the less-substituted carbon in the oxirane ring, resulting in its opening and formation of an OH group. The nitrogen of the amine group can attack another epoxy ring resulting in a highly branched polymer system, known as a thermoset, which presents high thermal stability and mechanical resistance [23]. This second nucleophilic attack of nitrogen can occur at the epoxy group of the resin or another molecule containing epoxy group, such as (3-glycidoxypropyl)trimethoxysilane (GPTMS) to produce an organic-inorganic hybrid structure (Figure 8).
Common epoxy resin precursors.
Bisphenol A diglycidyl ether.
Common curing agents.
Molecular structure of the epoxy-silica hybrid.
Simultaneously to the curing reaction, the sol-gel reactions of hydrolysis and condensation take place to produce the silica inorganic phase. GPTMS and TEOS Si–O–R groups, in presence of acidified water, become Si–OH through the hydrolysis reaction, and posteriorly, the Si–OH groups can condense with another Si–OH group or an initial Si–O–R group, forming Si–O–Si bonding and eliminating water or alcohol, respectively.
The surface characterization of the epoxy-silica hybrids deposited on carbon steel has shown that the coatings are uniform, transparent, smooth, and crack free (Figure 9). AFM images with an area of 1 μm2 were used to obtain the surface roughness of the coatings. Table 2 summarized all RMS surface roughness and thickness values determined for epoxy-silica hybrids of T-series (TEOS variation) and G-series (GPTMS variation). With increasing GPTMS and TEOS fraction, a significant increment of the surface roughness can be observed. The data suggest that increasing concentration of TEOS has a larger impact on the surface roughness than that of GPTMS, probably due to the formation of silica domains of larger size. Measurements of the films thickness indicate for all samples of the G-series a constant value of about 1.7 μm, while for films of the T-series the thickness varies from 2 to 3 μm, except for the T1.5 sample having 6.7 μm.
Representative image (a), and AFM image (b), of T1/G1 epoxy-silica hybrid coating deposited on carbon steel.
Samples | Thickness (μm) | RMS roughness (nm) | Cd (%) | α | Rg (nm) | d (nm) | T0 (°C) | EIS lifetime (days) |
---|---|---|---|---|---|---|---|---|
T0 | 3.0 | 0.3 | – | – | – | 3.7 | – | – |
T0.5 | 2.0 | 0.7 | 85.0 | 3.8 | – | 4.2 | 306 | 2 |
T1/G1 | 1.6 | 1.2 | 83.8 | 3.2 | 0.8 | – | 293 | 5 |
T1.5 | 6.7 | 0.3 | 87.1 | 3.9 | 0.8 | – | 314 | 42 |
T2 | 3.3 | 2.6 | 87.8 | 3.5 | 0.8 | – | 295 | 1 |
T2.5 | 1.8 | 5 | – | 3.4 | 0.8 | – | 302 | 4 |
G0.0 | 1.0 | – | – | 3.8 | – | – | – | – |
G0.5 | 1.8 | 0.6 | 87.8 | 1.8 | 1.5 | – | 285 | 55 |
G1.5 | 1.8 | 0.4 | 94.7 | 4.0 | 0.6 | – | 297 | – |
G2 | 1.6 | 1.0 | – | 4.0 | 0.4 | – | 304 | 1 |
G2.5 | 1.8 | 1.4 | – | 4.0 | 0.3 | – | 306 | 2 |
Properties of epoxy-silica hybrids: film thickness (optical interferometry); surface roughness (AFM); degree of polycondensation, Cd, (29Si-NMR); Porod coefficient, α, radius of gyration, Rg, and correlation distance, d, (SAXS); temperature of the limit of thermal stability T0 in N2 atmosphere (TGA); and coating lifetime in 3.5% NaCl (EIS).
Table 3 shows that results of the quantitative XPS analysis are in good agreement with those obtained for the nominal composition for both series of samples. As expected, the data show an increase of silicon and oxygen atomic concentration for the G and T-series, while nitrogen content increases slightly only for the G-series due to the higher DETA content. As the structure of GPTMS contains also carbon atoms, its addition leads to a less pronounced increase of the Si content. As a consequence, for the G-series the decrease of the C/Si ratio from 14.1 (G0.5) to 10.0 (G2.5) was smaller than that observed for the T-series from 15.9 (T0.5) to 8.3 (T2.5).
G0.5 | G2.5 | T0.5 | T2.5 | |||||
---|---|---|---|---|---|---|---|---|
XPS | Nominal | XPS | Nominal (at.%)* | XPS | Nominal | XPS | Nominal | |
Si 2p | 4.8 | 4.3 | 6.3 | 6.0 | 4.4 | 4.0 | 7.5 | 7.6 |
C 1s | 67.7 | 71.0 | 62.7 | 66.0 | 70.1 | 71 | 62.1 | 61.8 |
O 1s | 25.5 | 22.0 | 28.1 | 25.0 | 22.9 | 22.3 | 28.1 | 28.1 |
N 1s | 2.0 | 2.5 | 2.8 | 3.5 | 2.5 | 3 | 2.4 | 2.6 |
C/Si | 14.1 | 16.9 | 10.0 | 11.0 | 15.9 | 19 | 8.3 | 8.1 |
Comparison between XPS and calculated nominal atomic concentrations for epoxy-silica coatings.
*XPS experimental error ±5%.
The chemical bonding structure of the inorganic network can be characterized according to the proportion of different Si species having a fixed number of oxygen bridging silicon atoms bonded to one (central) silicon atom. A common notation is Qj for orthosilicates (0 ≤ j ≤ 4), such as TEOS, and Tj for organically modified silicates (0 ≤ j ≤ 3), such as GPTMS, where j gives the number of Si–O–Si bridges attached to the silicon atom.
Figure 10 shows the 29Si NMR spectra, fitted with Gaussian components, used to extract the proportion of Qj and Tj species. It can be observed that the Q4 and T3 peaks (−107 ppm and −62 ppm, respectively) have the highest intensities in relation to the other components related to lower network connectivity. The degree of connectivity of the inorganic phase, the so-called degree of polycondensation, Cd, has been determined from the fitted 29Si NMR spectra using the following equation:
29Si-NMR spectra obtained for epoxy-silica hybrids. Inset: schematic representation of the TJ and QJ species, where ‘R’ indicates OH or OCH3 or OCH2CH3 groups.
The Cd values of Table 3 show a high connectivity of the inorganic network with a clear predominance of a tetra-substituted TEOS and a tri-substituted GPTMS sites. Furthermore, it seems that an increase of GPTMS favors the Q4 and T3 structures, yielding a highly cross-linked inorganic network reaching about 95% connectivity for G1.5 sample, while the variation of TEOS does not change the Cd values significantly, remaining in the range of 85–88%. More information on the structure and size of the inorganic domains was obtained by small angle X-ray scattering (SAXS) measurements.
The SAXS technique allows to access the nanostructural characteristics of the inorganic network due to the higher electronic density of silica compared that of the polymeric matrix. The log-log plots of scattering intensities I (q) recorded for different fractions of GPTMS and TEOS (Figure 11) show three main characteristics: a linear decay located at low q values, corresponding to the Porod region; a Gaussian decay in the mid q-range, corresponding to the Guinier regime; and a broad correlation peak superimposed to the Guinier region, observed only for T0.0 and T0.5 samples. The former feature, in the mid q-range, is characteristic of a diluted set scatters, while the latter is the result of the interferences of the scattered X-ray caused by the concentrated set of nano-objects.
SAXS curves of T-series (a), and G-series (b), where the black lines represents the fits used to calculate the Porod coefficient (α) for q < 1 (except for the G0.5 sample, which presents α at q>1), and the radius of the gyration (Rg) for q >1. (The intensities were shifted to obtain a better visualization of the curves).
These scattering patterns have been already observed for other silica-polymer hybrids [24, 25] and attributed to a hierarchical organization of silica nano-domains. Accordingly, we propose that the nanostructure of the hybrid can be described by a two-level hierarchical model, corresponding to a diluted or concentrated (T0.0 and T0.5) set of silica nanoparticles inside the aggregation zones embedded in the polymer matrix. In the case of the diluted system, the size of the smaller particles was determined, in terms of the radius of the gyration, Rg, by fitting the Gaussian decay observed in the mid q-range using the Guinier model: I(q) = I0 exp (−Rg q2/3), where I0 is the scaling factor. However, this was only possible for scattering curves, which did not present an overlapping correlation peak. Therefore, values for Rg and those for the correlation distance, d ≈ 2π/q, have been obtained only for a restricted number of samples (Table 2). Except for T0.0, the form of the scattering objects was determined by fitting the curves using the Porod model: I ∝ q−α, where α is the Porod exponent. α ≈ 4 indicates a bi-phase system formed by set of nearly isometric scattering objects with a smooth surface, while for smaller values, a rough surface (fractal) is expected.
The results indicate that the inorganic phase consists of aggregates with relatively smooth surface and an average spacing of several nanometers (d ≈ 4 nm). These domains have been formedby agglomeration of smaller silica particles with a size of about 1 nm (0.3 < Rg < 1.5 nm).
Some clear correlations between these parameters and the increasing silica concentration of the G- and T-series could be established. For the G-series, the evolution of the SAXS pattern evidences the role of GPTMS in controlling the size of primary silica particles and they aggregation. The power law decay over a decade and α = 3.8 observed for the hybrid prepared only with TEOS (G0.0) characterizes the scattering by the surface of very large silica particles (>30 nm). The addition of a small amount of GPTMS (G0.5 sample) reduces the size of silica particles more than ten times (Rg = 1.5 nm) and prevents further aggregation, as evidenced by extended plateau at q < 0.1 nm. These unique features suggest for G0.5 sample an elevated nanostructural homogeneity, which might be responsible for the superior corrosion protection performance of this material (Table 2). In the case of the T-series, the correlation peak disappears for higher TEOS content and the linear decay shifts to higher q-values. These features evidence that TEOS addition favors the formation of more open aggregates, leading to a less compact nanostructure.
The thermal properties of the hybrids were studied by thermogravimetry under nitrogen flow. Table 2 shows the temperature of the limit of thermal stability, T0, for all epoxy-silica hybrids, defined as the temperature of 5% weight loss during the annealing process. The hybrids presented a thermal stability of about 300°C, relatively high values compared with those of other polymeric and hybrid materials [18, 22]. This advantageous property comes from the highly cross-linked structure provided by the curing agent (DETA) combined with the high polycondensation degree of the silica phase, as revealed by 29Si NMR.
Samples | Thickness (μm) | RMS roughness (nm) | Cd (%) | T0 (°C) | |Z| (GΩ cm2) | EIS lifetime (days) | Reference |
---|---|---|---|---|---|---|---|
M2 | 1.5 | – | 80.9 | – | ~0.001 | – | [21] |
M4 | – | – | 79.7 | – | ~0.01 | – | [21] |
M8 | 3 | 0.3 | 83.9 | – | ~1 | 18 | [21] |
M10 | – | – | 75.8 | – | ~0.001 | – | [21] |
M8_4h | 2.8 | 0.4 | 78.0 | 205 | ~0.1 | 56 | [18] |
M8_4h_E0.2 | 2.0 | 0.5 | 82.0 | 230 | ~3 | 196 | [10] |
M8_T80B0.01 | 2.8 | – | – | 230 | ~3 | 40 | – |
M8_T80B0.01* | 3.0 | – | – | – | ~50 | 560 | – |
M8_T90 | 2.6 | – | – | 238 | ~5 | 34 | – |
M8_T100 | 2.5 | – | – | 250 | ~0.1 | 35 | – |
M8_B0.05 | 5.0 | – | – | 270 | ~10 | 42 | – |
M8_B0.10 | 9.7 | – | – | 223 | ~10 | >186 | – |
Properties of PMMA-silica hybrid coatings: film thickness (optical interferometry); surface roughness (AFM); degree of polycondensation, Cd, (29Si-NMR); limit of thermal stability T0 in N2 atmosphere (TGA); impedance modulus |Z|, after 1 day exposure to 3.5% NaCl solution (EIS); and coating lifetime in 3.5% NaCl (EIS).
*Al2024 substrate.
The anticorrosive performance of the hybrids was assessed by EIS measurements, in a 3.5% NaCl saline solution at 25°C. The hybrid coatings deposited on carbon steel were attached to an electrochemical cell, and after verifying a constant value of the open-circuit potential, the impedance measurements were performed as a function of time until a significative drop of the impedance modulus occurred. This time period was defined as lifetime of the coating, listed in Table 2. The impedance modulus at low frequency of the Bode plot is generally used as an indicator of the anticorrosive performance of the coating, with values higher than 0.1 GΩ cm−2 typically considered an excellent protection. The corrosion resistance of the films generally decreases with time, caused by the penetration of electrolyte into the protective layer through zones of residual porosity and defects.
The Nyquist and Bode plots obtained after 1 day of immersion in 3.5% NaCl solution are presented in Figure 12. It can be observed that two samples containing intermediate TEOS to GPTMS ratios (T1.5 and G0.5) presented the highest impedance modulus of 0.9 and 0.2 GΩ cm2, respectively, and showed also the longest lifetime of several weeks (Table 2). These coatings show at higher frequencies (>1 Hz), a capacitive behavior with a phase angle higher than −80° extending over a range of 4 decades, characteristic for an efficient anticorrosive barrier layer. In contrast, for formulations with excess of TEOS or GPTMS, both the corrosion resistance and lifetime values show considerably lower values.
Nyquist and Bode plots of (a) series T and (b) series G of the epoxy-silica coatings deposited on carbon steel, compared to those of bare carbon steel, after 1 h of immersion in 3.5% NaCl solution.
The results of the structural analysis indicate that the excellent barrier properties, found for coatings with intermediate TEOS to GPTMS ratio, result from a highly reticulated hybrid structure combining a number of favorable properties, such as a high polycondensation degree of the inorganic phase, a extremely smooth surface, indicating a very homogeneous distribution of silica nanodomains, high thermal stability, as well as an adequate quantity of the silica phase which ensures a good adhesion of the film to the metallic substrate. Although the corrosion protection efficiency of the best epoxy-silica coatings, reported so far [7, 26, 27], is comparable with results presented in this work, it may profit from their 10–100 times higher thickness.
Poly(methyl methacrylate), also known as acrylic and Pexiglas®, is a rigid, low cost, nontoxic, transparent and colorless thermoplastic polymer, extensively used as optical lenses, protective coatings, optical fibers, and as an alternative to glass in windows as well as a variety of household appliances. The introduction of an inorganic component, such as silica, improves the thermal stability, mechanical strength, and the adhesion to metallic substrates, the latter property being an essential feature for a high-efficiency coatings. The covalent bond between the PMMA and the silica phase can be achieved by the addition of 3-(trimethoxysilyl)propyl methacrylate (MPTS), a coupling agent formed by an alkoxy-silane group attached by a nonhydrolysable Si–C bond to the acrylic tail, which polymerizes with PMMA chains, while the inorganic part reacts with the silica precursor (TEOS), yielding an organic-inorganic hybrid structure, shown in Figure 13.
Molecular structure of the PMMA-silica hybrid.
A variety of PMMA-silica hybrids have been studied, changing the organic/inorganic phase proportion, the amount of thermal initiator, the synthesis temperature and time, as well as the ethanol-to-water ratio. Furthermore, cerium salt has been added to the PMMA-silica matrix as corrosion inhibitor, and lignin, carbon nanotubes, and graphene oxide as fillers. The main results, found for pure PMMA-silica hybrids, are summarized in Table 4, those obtained using additives will be discussed in the following sections.
Similar to epoxy-silica coatings, PMMA-silica hybrids deposited on metallic substrates were homogeneous, transparent and had a very smooth surface. Structural analysis of PMMA-silica hybrids, performed by AFM, SAXS, NMR and XPS, has shown that the nanostructure is formed by a dense amorphous network of ramified silica-siloxane cross-link nodes, covalently interconnected by short PMMA chain segments [10, 22]. Varying the MMA/MPTS molar ratio from 2 to 10, NMR and SAXS results have shown that the M8 sample (MMA/MPTS = 8) presented the highest degree of polycondensation (83.9%) of the silica nanoparticles with an average radius of 0.8 nm, spaced by PMMA segments over an average distance of 4.6 nm. This coating exhibited also an excellent adhesion to the substrate (detachment force > 3.5 MPa) and the best anti-corrosion performance [10, 22]. EIS and potentiodynamic polarization results have shown that the M8 coating deposited on carbon steel acts as a very efficient corrosion barrier, increasing the total corrosion resistance by almost 6 orders of magnitude (>1 GΩ cm2) and reducing the current densities by more than 4 orders of magnitude (<0.1 nA cm−2), compared to the bare steel substrate [22]. Furthermore, XPS analysis confirmed that no corrosion-induced changes had occurred after 18 days of immersion in 3.5% NaCl solution [22].
Increasing the synthesis temperature from 70 to 80°C and the time of reaction from 2 to 4 h (sample M8_4h), an increase in the amount of polymeric phase was detected yielding a more compact and durable coating (56 days) [18, 22]. After optimizing also the ethanol-to-water ratio of the inorganic phase to a value of 0.2, the corrosion resistance and lifetime were further increase to 196 days in 3.5% NaCl (M8_4h_E0.2 coating, Table 4) [10]. Other important finding was the improvement of the corrosion resistance by hot deposition (M8_T80B0.01), which enhances the reaction between the inorganic phase and the metal substrate, improving the coating adhesion. This sample has been also deposited on Al2024 substrate and tested in saline (Figure 14a) and saline/acid environment (Figure 14b). This coating highlights a corrosion resistance of up to 50 GΩ cm2, in saline environment, showing only a small performance decrease to 0.1 GΩ cm2 after 560 days exposure. This is to our best knowledge the highest durability, obtained so far for hybrid coatings in standard saline solution. Also in contact with a saline/acid solution (0.05 mol L−1 H2SO4 + 0.05 mol L−1 NaCl), this about 3-μm thick coating presented a high corrosion resistance (20 GΩ cm2), remaining almost unchanged during its lifetime of 87 days. It is interesting to note that the phase angle dependence has a capacitive behavior (θ ≈ −90°), over a frequency range of 6 decades, a behavior close to that of an ideal capacitor, highlighting the extraordinary performance of this coating.
Time dependence of Nyquist and Bode plots of the M8_T80BPO0.01 PMMA-silica coating deposited on Al2024 substrate in contact with a) in 3.5% NaCl solution and b) 0.05 mol L−1 NaCl + 0.05 mol L−1 H2SO4 solution.
Molecular structure of (a) lignin, (b) carbon nanotube, and (c) graphene oxide.
PMMA-silica hybrids have been also prepared at different synthesis temperatures of the organic precursor (80–100°C) and different BPO/MMA molar ratio (0.01–0.1), using the well-established MMA/MPTS molar ratio of 8 [22]. The increase in the synthesis temperature did not influence significantly the structure, the thermal properties and the corrosion resistance, however, the increase of the BPO amount led to an increase of the polymerization degree, thermal stability of 40°C (BPO0.05), and also of the anticorrosive efficiency (Table 4). The sample M8_BPO0.05 and M8_BPO0.10 presented an impedance modulus of 10 GΩ cm2 in a saline medium (3.5% NaCl), remaining essentially unchanged during more than 6 months of exposure (M8_BPO0.10).
After identifying the optimum proportion of polymeric and silica phase for the formation of a highly ramified structure (MMA/MPTS/TEOS molar ratio = 8/1/2), increasing molar percentage of Ce(IV) ions (0.1% < Ce/Si < 5%) have been added to the inorganic precursor to enhance the passivating character of the films [11].
NMR, XPS, and SAXS results, summarized in Table 5, have revealed the active role of Ce(IV) in the PMMA-silica matrix. The correlation of XPS and NMR data evidenced that the Ce(IV) concentration is directly related to the polycondensation degree (Cd) and the degree of Ce(IV) reduction, both decreasing with increasing cerium concentration. Low concentrations of cerium lead to an enhanced polycondensation of the siloxane/silica phase, with connectivity of the inorganic phase up to 87%. For low doping levels of Ce/Si < 0.7%, SAXS results have revealed increasing values of radius of gyration, Rg, suggesting an active role of Ce(IV) as oxidation agent in the enhanced growth of a cross-linked and polycondensed inorganic phase. Detailed investigation of the structural effects of cerium species has shown that reduction of Ce(IV) ions not only catalyzes a higher connectivity of the silica phase, but also enhances the polymerization of organic moieties. The resulting enhancement of the overall network connectivity leads to an improvement of the thermal stability of the hybrids, as evidenced by the results of the thermogravimetric analysis [11].
Properties | Ce(IV)/Si molar fraction (%) | ||||||||
---|---|---|---|---|---|---|---|---|---|
0 | 0.1 | 0.2 | 0.3 | 0.5 | 0.7 | 1 | 3 | 5 | |
Cd (%) | 82.8 | 87.1 | – | 83.6 | 82.7 | 79.3 | 78.5 | 77.6 | 77.3 |
XPS Ce(IV) fraction (%) | – | – | – | 28.5 ± 4 | 37.2 ± 3 | 46.4 ± 2.5 | 48.5 ± 2.5 | 55.5 ± 2 | 60.4 ± 1.5 |
Rg (nm) | 0.9 | 1.1 | 1.8 | 2.3 | 2.3 | 1.9 | 1.9 | – | – |
|Z| (GΩ cm2) | ~0.5 | ~0.5 | – | – | ~0.1 | ~10 | ~5 | – | ~0.5 |
Lifetime (days) | 42 | 85 | – | 96 | – | 304 | 65 | 48 | 404 |
Properties of PMMA-silica hybrids containing different amounts of Ce(IV): degree of polycondensation, Cd, (29Si-NMR); percentage of the Ce(IV) oxidation state (XPS Ce 3d spectra); radius of gyration, Rg, (SAXS); and impedance modulus, |Z|, after 1 day exposure to 3.5% NaCl solution (EIS).
The electrochemical assays, performed by EIS and potentiodynamic polarization curves, have shown that the PMMA-silica coatings containing intermediate concentrations of cerium present a combination of high-corrosion resistance (~10 GΩ cm2), elevated overpotential stability at low-current densities (<10−11 A), as well as excellent long-term stability of up to 304 days. Compared to the bare carbon steel substrate, the coated samples showed up to 6 orders of magnitude higher impedance modulus and up to 6 orders of magnitude lower current densities [11].
For coatings containing elevated Ce(IV) doping levels (Si/Ce = 5%), the self-healing effect was observed, induced by the formation of insoluble cerium oxides and hydroxides in corrosion affected regions. The presence of these phases in the near surface region was evidenced by XPS O 1s spectra and by scanning electron microscopy, showing the presence of nanopits (<300 nm). It was suggested that these phases were formed by reactions of Ce(III) and Ce(IV) with water and residual hydroxyl groups of the hybrid. The self-healing process prevented the progression of the corrosion process for more than 13 months keeping the corrosion resistance constant above 0.01 GΩ cm2. The excellent anticorrosive efficiency achieved by PMMA-silica coatings containing cerium can be related to a double effect of Ce(IV), combining the densification of the hybrid network with the formation of insoluble cerium species in regions affected by pitting [11].
Lignin is a macromolecule present in the cell walls of terrestrial plants that confers rigidity and impermeability, usually corresponding to 15–30% of the dry weight of wood (Figure 15a). Presently, millions of tons of lignin are generated from biodiesel and ethanol production, and most part is incinerated to generate electric energy. However, nobler applications have been found to add value to this biomass, such as the reinforcement of different classes of materials. Properties, such as low density, low abrasive character, hydrophobicity, and low cost, make lignin ideal to use as filler in polymeric and organic-inorganic hybrid matrices [20].
Carbon nanotubes (CNTs) and graphene oxide (GO) (Figure 15b and c) are also very interesting nanofillers for the structural reinforcement of polymeric and hybrid materials, due to their exceptional thermal, chemical, and mechanical resistance. Both present a hexagonal sp2 arrangement of carbon atoms, forming extremely stable cylindrical and monolayer structures, respectively. Graphene oxide has been obtained from oxidation and exfoliation of graphite, yielding a graphene layer containing oxygen functional groups such as epoxy, hydroxyl, and carboxyl [18].
PMMA-silica hybrids reinforced with 0.05, 0.10, 0.50 and 1.00 wt.% of lignin have been deposited on carbon steel by dip-coating, producing about 2.5 μm thick coatings (Table 6). Optical microscopy and optical microscopy and atomic force microscopy showed that lignin was well dispersed in the hybrid matrix, and all coatings presented a low RMS surface roughness between 0.3 and 0.4 nm. The introduction of lignin in the PMMA-silica hybrid increased the water contact angle of the film surface from 79.3° to 87.9°, the hardness from 22.9 to 30.9 HV, and the scratch resistance (critical load for delamination) from 55 to 80 mN. In addition, the thermal degradation events, obtained by thermogravimetric analysis (TGA) under nitrogen atmosphere, were shifted to higher temperatures with lignin addition, due to its phenolic structure which has the ability to trap radicals formed during the depolymerisation. Besides increasing the thermal stability of the polymeric phase, it acts also as UV stabilizer [20].
Sample | Thickness(μm) | T0 (°C) | Critical load (mN) | |Z| (GΩ cm2) | EIS lifetime (days) | Reference |
---|---|---|---|---|---|---|
M8 (70°C/2 h) | 2.4 | 170 | 55 | ~0.1 | 18 | [20] |
M8_lignin_0.50 wt.% | 2.6 | 180 | 65 | ~0.5 | – | [20] |
M8_lignin_0.10 wt.% | 2.5 | 200 | 80 | ~0.5 | 50 | [20] |
M8_lignin_0.50 wt.% | 2.7 | 190 | 66 | ~0.01 | – | [20] |
M8_lignin_1.00 wt.% | 2.7 | 195 | 56 | ~0.005 | – | [20] |
M8_BPO001(80°C/4 h) | 2.8 | 205 | 78 | ~0.5 | 56 | [18] |
M8_BPO001_CNT_0.05% | 5.7 | 220 | – | ~0.1 | 43 | [18] |
M8_BPO001_GO_0.05% | 3.1 | 275 | 94 | ~1 | 203 | [18] |
M8_BPO005(80°C/4 h) | 3.5 | 208 | 84 | ~1 | 21 | [18] |
M8_BPO005_CNT_0.05% | 6.6 | 209 | 133 | ~10 | 7 | [18] |
M8_BPO005_GO_0.05% | 5.5 | 216 | 148 | ~5 | 168 | [18] |
Properties of PMMA-silica hybrids containing lignin, CNT or GO: film thickness (optical interferometry); limit of thermal stability T0 in N2 atmosphere (TGA); critical load for delamination (microscrach test); impedance modulus |Z|, after 1 day exposure to 3.5% NaCl solution (EIS); and coating lifetime in 3.5% NaCl (EIS).
The electrochemical tests performed by EIS showed that the PMMA-silica coatings containing lignin act as efficient diffusion barriers, with corrosion resistance higher than 0.1 GΩ cm2 after exposure to 3.5% NaCl aqueous solution. For intermediate lignin content of 0.10 wt.% the coatings presented best results with an impedance modulus of 0.5 GΩ cm2, remaining almost unchanged after 50 days of exposure to aggressive environment [20].
Recent studies on the inclusion of carbon nanotubes and graphene oxide in hybrid and polymer matrices have shown excellent results in terms of increased mechanical strength, scratch and wear resistance, thermal stability, adhesion to metallic substrate, hydrophobicity, and electrical conductivity [18, 19, 28–30]. Despite all of these advances, a simultaneous improvement not only of mechanical and thermal stability but also of anticorrosive efficiency of protective coatings has been accomplished only recently by the incorporation CNT and GO in a PMMA-silica matrix [18].
To synthesize the CNT and GO modified PMMA-silica hybrids, first, the single-walled carbon nanotubes and graphene oxide were dispersed in a water/ethanol, adding in the case of CNTs dodecyl sulfate surfactant (SDS) as dispersant. Then, the carbon nanostructures were added to the inorganic precursor solution of the PMMA-silica hybrid at a carbon (CNT or GO) to silicon (TEOS and MPTS) molar ratio of 0.05% in two different matrices, prepared at BPO/MMA molar ratios of 0.01 and 0.05. As the function of BPO as a thermal initiator is to produce radicals that initiate the polymerization process of MMA, an increased BPO content results in enhanced polymerization degree in the hybrid. The transparent hybrids deposited on A1020 carbon steel substrates by dip coating presented thickness values between 2.8 and 6.6 μm (Table 6), a good dispersion of the carbon nanostructures, and a very smooth surface (0.3–0.5 nm RMS surface roughness) [18].
Hybrid | Synthesis | Substrate | Deposition/thickness (μm) | EIS: |Z| (GΩ cm2), lifetime (days), solution | PolarizationIcorr (A cm−2)Ecorr (V), reference electrode | Reference |
---|---|---|---|---|---|---|
Epoxy-GPTMS-TEOS | Sol-gel | Carbon steel | Dip-coating/6.7 | ~1 42 3.5% NaCl | _ −0.08 Ag/AgCl | [This work] |
Epoxy-APTES-ZnO | Sol-gel | Mg alloy AZ31 | Dip-coating/~12 | ~1 35 0.05 M NaCl | _ | [33] |
Epoxy-APTES | _ | Carbon steel | Spray/125 | ~100 21 0.1 M Na2SO4 | _ | [27] |
Epoxy-SiO2 | Sol-gel | Mg alloy | Dip-coating/- | ~100 7 3.5% NaCl | _ | [34] |
Epoxy-APTES | Solution intercalation method | Mild steel | Brush method/70–80 | ~10 30 3% NaCl | _ | [35] |
Epoxy-APTES-tetrathiol | Sol-gel | Al alloy AA2024-T3 | Single blade/150 | ~1 350 0.5 M NaCl | _ | [26] |
Epoxy-polysiloxane | Commercial | Cold rolled low carbon steel | Air-less spray/70 | ~100 467 3% NaCl | _ −0.65 SCE | [7] |
GPTMS-MTEOS-TEOS | Sol-gel | Al alloy AA2024-T3 | Dip-coating/25 | ~0.1 38 5% NaCl | _ | [36] |
Epoxy-APTES | _ | Mg alloy AZ31 | Dip-coating/14 | ~10 31 0.5 M NaCl | _ | [37] |
Epoxy-GPTMS-MTEOS/- | Sol-gel | Al alloy AA2024 | Dip-coating/~8 | ~1 51 0.05 M NaCl | 10−10 −0.3 Ag/AgCl | [38] |
Principal preparation parameters and results reported for epoxy-silica coatings applied for corrosion protection of metallic surfaces, including corrosion resistance |Z|, current density, Icorr, and corrosion potential, Ecorr.
GPTMS: (3-glycidoxypropyl)trimethoxysilane; TEOS: tetraethoxysilane; APTES: aminopropyl-triethoxysilane; tetrathiol: pentaerythritol tetrakis(3-mercaptopropionate); MTEOS: methyl-triethoxysilane; SCE: standard calomel electrode.
Microscratch and wear tests, performed with a spherical-conical diamond tip of 10 μm radius, confirmed for the PMMA-silica coatings that both additives, CNT and GO, improved the scratch resistance (increase of the friction coefficient by 0.1−0.2), adhesion to the metallic substrate (no delamination for M8_BPO001_CNT up to 240 mN) and wear resistance (smooth and shallow wear track after 50 cycles). The superior behavior of CNT containing coatings was attributed to their property to act as rigid obstacles for the scratch tip. Results of the thermogravimetric analysis have shown that the addition of CNT and GO to the BPO0.01 matrix and to a smaller extent to the BPO0.05 matrix, increased the thermal stability of the hybrids up to 70°C for GO containing samples (Table 6). This improvement was attributed to interaction between carbon nanostructures and macroradicals generated during the process of depolymerisation combined with a 2D barrier effect of GO, hindering molecular diffusion through the matrix and thus providing an improved thermal resistance [18].
Results of electrochemical impedance spectroscopy in 3.5% NaCl solution showed that PMMA-silica coatings reinforced with CNTs and GO had an improved anticorrosive efficiency, with impedance modulus of ~1 GΩ cm2 and ~10 GΩ cm2 for the BPO0.01 and BPO0.05 matrix, respectively. Besides the improved barrier property, GO containing coatings presented also a prolonged lifetime of up to 203 days. This was attributed to the two dimensionality of the GO structure that provides an enhanced barrier effect against the propagation of corrosive species. Furthermore, it was suggested that both carbon nanostructures act as densifiers of the nanocomposite and also as negatively charged repulsive agents for chloride anions, thus improving barrier property of the coating. Based on the equivalent circuit used to fit the EIS data, this notable barrier behavior was interpreted, in terms of two distinct dielectric layers, one related to a porous water uptake zone at the coating/electrolyte interface and the other corresponding to the underlying unaffected film region, having three orders of magnitude higher resistivity [18].
To be able to evaluate the relevance of the obtained results, it is important to place them in the context of the state of the art in the field of anticorrosive coatings. In the last decade, the concept of organic-inorganic hybrids as protective coating has been intensely investigated using different approaches involving a variety of organic and inorganic precursor reagents, resulting in a number of promising coatings systems. The most widely applied formulations for hybrid phases used to prepare high-performance anticorrosive coatings are based on epoxy-silica (Table 7) and acrylic-silica (Table 8) hybrids, and to a lower extent on polyurethane-silica, polyurethane-silica-zirconia and other epoxy systems (Table 9). As can be inferred from these data, the electrochemical barrier properties, obtained for different hybrid formulations, have achieved a notable performance in the last years, making these novel nanocomposites very promising candidates for efficient corrosion protection of metallic surfaces. This is justified especially when considering that a high-corrosion resistance and long durability in aggressive environments can be achieved by thin films with thicknesses of less than 10 μm, resulting in substantially reduced material costs compared to conventional high-performance coating systems. More specifically, regarding the epoxy-silica hybrid system, the results presented in this work and those listed in Table 7 show that different compositions applied to distinct alloys can provide a very effective long-term corrosion protection [7, 26, 27]. Very promising results were also achieved for PMMA-silica coatings [8, 10, 31], with the highest observed durability of more than 560 days in 3.5% NaCl, and for hybrids containing reinforcement and inhibitor agents [11, 18]. Moreover, for some polyurethane-silica and polyurethane-zirconia-silica systems, it has been demonstrated that they also have a high potential to be used as efficient anticorrosive barrier layers [9, 32].
Hybrid/additive | Synthesis | Substrate | Deposition/thickness (μm) | EIS: |Z| (GΩ cm2), lifetime (days), solution | PolarizationIcorr (A cm−2) Ecorr (V), reference electrode | Reference |
---|---|---|---|---|---|---|
PMMA-MPTS-TEOS/- | Radical polymerization and sol-gel | Al alloy AA2024 | Dip-coating/~3 | ~50 more than 560 3.5% NaCl | _ −0.68 Ag/AgCl | [This work] |
PMMA-MPTS-TEOS/- | Sol-gel | 316L stainless steel | Dip-coating/~2 | ~0.01 36 3.5% NaCl | 10−9 0.1 Ag/AgCl | [14] |
GMA-EHA-GPTMS-TEOS/- | Sol-gel | Al alloys AA1050 | Spin-coating/~1 | ~1 21 0.1 M NaCl | _ | [39] |
PMMA-MPTS-TEOS/- | Sol-gel | A1010 carbon steel | Dip-coating/1.5–3 | ~1 18 3.5% NaCl | 10−10 −0.3 Ag/AgCl | [22] |
PMMA-MPTS-TEOS/Ce(IV) | Radical polymerization and sol-gel | A1010 carbon steel | Dip-coating/~2 | ~10 304/404 3.5% NaCl | 10−11 + 0.3 Ag/AgCl | [11] |
PMMA-MPTS-TEOS/ lignin | Radical polymerization and sol-gel | A1020 carbon steel | Dip-coating/~2 | ~0.5 50 3.5% NaCl | _ | [20] |
PMMA-MPTS-TEOS/- | Radical polymerization and sol-gel | A1010 carbon steel | Dip-coating/1.5–2 | ~5 196 3.5% NaCl | _ | [10] |
PMMA-MPTSTEOS/Ce | Sol-gel | Mild steel | Dip-coating/~26 | ~10 362 3.5% NaCl | 10−12 + 0.35 SCE | [31] |
Acrylic resin-SiO2/- | Solution intercalation method | Mild steel | Brush method/75 | ~10 90 3.5% NaCl | _ | [8] |
Acrylic resin-silanol-ZnO/- | Solution intercalation method | Mild steel | Brush method/75 | ~10 30 3.5% NaCl | _ | [40] |
PMMA-MPTS-TEOS/CNTs, GO | Radical polymerization and sol-gel | A1020 carbon steel | Dip-coating/3–6 | ~3 211 3.5% NaCl | _ +0.58 Ag/AgCl | [18] |
Principal preparation parameters and results reported for acrylic-silica coatings applied for corrosion protection of metallic surfaces, including corrosion resistance |Z|, current density Icorr, and corrosion potential Ecorr.
PMMA: poly(methyl methacrylate); MPTS: 3-(trimethoxysilyl)propyl methacrylate; TEOS: tetraethoxysilane; GMA: glycidyl methacrylate; EHA: 2-ethylhexyl acrylate; GPTMS: (3-glycidoxypropyl) trimethoxysilane;CNTs: carbon nanotubes; GO:graphene oxide; SCE: standard calomel electrode.
Hybrid/additive | Synthesis | Substrate | Deposition/thickness (μm) | EIS: |Z| (GΩ cm2), lifetime (days), solution | Polarization,Icorr(A cm−2),Ecorr (V),reference electrode | Reference |
---|---|---|---|---|---|---|
Polyurethane APTES-TEOS/- | _ | AA3003 H14 | Drawdown bar/75 | ~100 263 3.5%NaCl+0.1M HCl | _ | [9] |
Polyurethane-ZrO2-SiO2/- | Sol-gel | Carbon steel | Spray/40–55 | ~100 226 3.5% NaCl | _ | [32] |
Epoxy-polyaniline-ZnO/- | Chemical oxidative method | Carbon steel | Dip-coating/118 | ~1 90 3.5% NaCl | _ −0.05 (SCE) | [41] |
Polyetherimide-HA/- | _ | Mg alloy AZ31 | Dip-coating/~4 | ~1 101 Hank’s solution | _ | [42] |
Epoxy-LDH/- | _ | Al alloy AA2024-T3 | Spray/55 | ~1 18 0.05M NaCl | _ | [43] |
Epoxy-HS/8-hydroyquinoline | _ | Al alloy AA2024-T3 | Dip-coating/~25 | ~1 90 0.5M NaCl | _ | [44] |
Epoxy-CaCO3 | _ | Al alloy AA2024-T3 | Dip-coating/~30 | ~1 41 0.5M NaCl | _ | [45] |
Epoxy-ester-siloxane-urea | _ | Al alloy AA2024-T3 | Drop-coating/130–140 | ~0.1 70 3.5% NaCl | 10−10 −0.4 SCE | [46] |
Principal preparation parameters and results reported for a varied of hybrid coatings applied for corrosion protection of metallic surfaces, including corrosion resistance |Z|, current density Icorr, and corrosion potential Ecorr.
APTES: aminopropyltriethoxysilane; TEOS: tetraethoxysilane; HA: hydroxyapatite; LDH: Layered double hydroxide; HS: halloysites; CaCO3: calcium carbonate; SCE: standard calomel electrode.
All these results demonstrate the wealth of possibilities to prepare nanocomposite materials based on organic-inorganic hybrids in the form of highly efficient anticorrosive coatings. The optimization of the barrier property can be achieved by the careful adjustment of the precursor proportions, including coupling agents and additives, together with the conditions of synthesis, deposition, and thermal treatment. However, the main key for this task is an in-depth knowledge of the formation mechanisms as well as the compositional and structural properties of the material. Based on this information, it was shown that a relatively simple preparation process yields highly efficient and very durable anticorrosive films. They unite three essential perquisites for an appropriate coating system: a high corrosion resistance, long-term stability, and environmental compatibility. Considering also the simplicity of the sol-gel process and the low material consumption, which scales with the film thickness, these about 5-μm thick hybrid films constitute from the economical and environmental point of view a very interesting alternative for conventional protective coating systems.
Structural, thermal, mechanical, and electrochemical characterization of novel epoxy-silica and PMMA-silica hybrid coatings have shown that their properties are extremely dependent of the hybrid precursors proportion, time and temperature of synthesis, and addition of fillers. After a careful adjustment of the preparation conditions, these homogeneous and transparent hybrid coatings present a defect-free very smooth surface, low porosity, a highly cross-linked silica network, excellent adhesion to the metallic substrate, elevated thermal stability, and especially an excellent anticorrosive performance. Epoxy-silica and PMMA-silica films with thicknesses of less than 10 μm exhibit a dense and highly reticulated nanostructure, resulting in enhanced thermal stability combined with high corrosion resistance and long durability in saline environment. Exceptional barrier properties, especially on aluminum alloy, were found for PMMA-silica hybrids prepared at a 8MMA:1MPTS:2TEOS molar ratio, 4 h/80°C of synthesis, and BPO/MMA molar ratio of 0.01. This coating highlights a corrosion resistance of about 50 GΩ cm2 and a lifetime of more than 18 months in saline solution. Nanofillers have been successfully added to the PMMA-silica matrix to improve the anticorrosive performance and to reinforce the hybrid structure. Carbon nanotubes and graphene oxide incorporated into the PMMA-silica matrix resulted in a multifunctional material, which combines an excellent anticorrosive performance with improved adhesion, anti-scratch and heat-resistant properties, thus extending the application range of these coatings to abrasive environments. Furthermore, it has been shown that added Ce(IV) ions act as oxidation agents during the formation of the hybrid matrix, leading to densification process that improves the barrier property of the coatings. In addition, the active corrosion inhibition provided by formation of insoluble cerium species in regions affected by corrosion, known as self-healing ability, resulted in a prolonged the lifetime of the coatings. The great progress achieved in the last couple of years in the development of organic-inorganic hybrids makes these materials very promising candidates for new-generation high-performance protective coatings.
We would like to thank the National Laboratory of Synchrotron Light Source (LNLS, Brazil) for the use of SAXS facilities. This work was supported by the Brazilian funding agencies CNPq, CAPES, and FAPESP.
Research methodology is the path through which researchers need to conduct their research. It shows the path through which these researchers formulate their problem and objective and present their result from the data obtained during the study period. This research design and methodology chapter also shows how the research outcome at the end will be obtained in line with meeting the objective of the study. This chapter hence discusses the research methods that were used during the research process. It includes the research methodology of the study from the research strategy to the result dissemination. For emphasis, in this chapter, the author outlines the research strategy, research design, research methodology, the study area, data sources such as primary data sources and secondary data, population consideration and sample size determination such as questionnaires sample size determination and workplace site exposure measurement sample determination, data collection methods like primary data collection methods including workplace site observation data collection and data collection through desk review, data collection through questionnaires, data obtained from experts opinion, workplace site exposure measurement, data collection tools pretest, secondary data collection methods, methods of data analysis used such as quantitative data analysis and qualitative data analysis, data analysis software, the reliability and validity analysis of the quantitative data, reliability of data, reliability analysis, validity, data quality management, inclusion criteria, ethical consideration and dissemination of result and its utilization approaches. In order to satisfy the objectives of the study, a qualitative and quantitative research method is apprehended in general. The study used these mixed strategies because the data were obtained from all aspects of the data source during the study time. Therefore, the purpose of this methodology is to satisfy the research plan and target devised by the researcher.
The research design is intended to provide an appropriate framework for a study. A very significant decision in research design process is the choice to be made regarding research approach since it determines how relevant information for a study will be obtained; however, the research design process involves many interrelated decisions [1].
This study employed a mixed type of methods. The first part of the study consisted of a series of well-structured questionnaires (for management, employee’s representatives, and technician of industries) and semi-structured interviews with key stakeholders (government bodies, ministries, and industries) in participating organizations. The other design used is an interview of employees to know how they feel about safety and health of their workplace, and field observation at the selected industrial sites was undertaken.
Hence, this study employs a descriptive research design to agree on the effects of occupational safety and health management system on employee health, safety, and property damage for selected manufacturing industries. Saunders et al. [2] and Miller [3] say that descriptive research portrays an accurate profile of persons, events, or situations. This design offers to the researchers a profile of described relevant aspects of the phenomena of interest from an individual, organizational, and industry-oriented perspective. Therefore, this research design enabled the researchers to gather data from a wide range of respondents on the impact of safety and health on manufacturing industries in Ethiopia. And this helped in analyzing the response obtained on how it affects the manufacturing industries’ workplace safety and health. The research overall design and flow process are depicted in Figure 1.
Research methods and processes (author design).
To address the key research objectives, this research used both qualitative and quantitative methods and combination of primary and secondary sources. The qualitative data supports the quantitative data analysis and results. The result obtained is triangulated since the researcher utilized the qualitative and quantitative data types in the data analysis. The study area, data sources, and sampling techniques were discussed under this section.
According to Fraenkel and Warren [4] studies, population refers to the complete set of individuals (subjects or events) having common characteristics in which the researcher is interested. The population of the study was determined based on random sampling system. This data collection was conducted from March 07, 2015 to December 10, 2016, from selected manufacturing industries found in Addis Ababa city and around. The manufacturing companies were selected based on their employee number, established year, and the potential accidents prevailing and the manufacturing industry type even though all criterions were difficult to satisfy.
It was obtained from the original source of information. The primary data were more reliable and have more confidence level of decision-making with the trusted analysis having direct intact with occurrence of the events. The primary data sources are industries’ working environment (through observation, pictures, and photograph) and industry employees (management and bottom workers) (interview, questionnaires and discussions).
Desk review has been conducted to collect data from various secondary sources. This includes reports and project documents at each manufacturing sectors (more on medium and large level). Secondary data sources have been obtained from literatures regarding OSH, and the remaining data were from the companies’ manuals, reports, and some management documents which were included under the desk review. Reputable journals, books, different articles, periodicals, proceedings, magazines, newsletters, newspapers, websites, and other sources were considered on the manufacturing industrial sectors. The data also obtained from the existing working documents, manuals, procedures, reports, statistical data, policies, regulations, and standards were taken into account for the review.
In general, for this research study, the desk review has been completed to this end, and it had been polished and modified upon manuals and documents obtained from the selected companies.
The study population consisted of manufacturing industries’ employees in Addis Ababa city and around as there are more representative manufacturing industrial clusters found. To select representative manufacturing industrial sector population, the types of the industries expected were more potential to accidents based on random and purposive sampling considered. The population of data was from textile, leather, metal, chemicals, and food manufacturing industries. A total of 189 sample sizes of industries responded to the questionnaire survey from the priority areas of the government. Random sample sizes and disproportionate methods were used, and 80 from wood, metal, and iron works; 30 from food, beverage, and tobacco products; 50 from leather, textile, and garments; 20 from chemical and chemical products; and 9 from other remaining 9 clusters of manufacturing industries responded.
A simple random sampling and purposive sampling methods were used to select the representative manufacturing industries and respondents for the study. The simple random sampling ensures that each member of the population has an equal chance for the selection or the chance of getting a response which can be more than equal to the chance depending on the data analysis justification. Sample size determination procedure was used to get optimum and reasonable information. In this study, both probability (simple random sampling) and nonprobability (convenience, quota, purposive, and judgmental) sampling methods were used as the nature of the industries are varied. This is because of the characteristics of data sources which permitted the researchers to follow the multi-methods. This helps the analysis to triangulate the data obtained and increase the reliability of the research outcome and its decision. The companies’ establishment time and its engagement in operation, the number of employees and the proportion it has, the owner types (government and private), type of manufacturing industry/production, types of resource used at work, and the location it is found in the city and around were some of the criteria for the selections.
The determination of the sample size was adopted from Daniel [5] and Cochran [6] formula. The formula used was for unknown population size Eq. (1) and is given as
where n = sample size, Z = statistic for a level of confidence, P = expected prevalence or proportion (in proportion of one; if 50%, P = 0.5), and d = precision (in proportion of one; if 6%, d = 0.06). Z statistic (Z): for the level of confidence of 95%, which is conventional, Z value is 1.96. In this study, investigators present their results with 95% confidence intervals (CI).
The expected sample number was 267 at the marginal error of 6% for 95% confidence interval of manufacturing industries. However, the collected data indicated that only 189 populations were used for the analysis after rejecting some data having more missing values in the responses from the industries. Hence, the actual data collection resulted in 71% response rate. The 267 population were assumed to be satisfactory and representative for the data analysis.
The sample size for the experimental exposure measurements of physical work environment has been considered based on the physical data prepared for questionnaires and respondents. The response of positive were considered for exposure measurement factors to be considered for the physical environment health and disease causing such as noise intensity, light intensity, pressure/stress, vibration, temperature/coldness, or hotness and dust particles on 20 workplace sites. The selection method was using random sampling in line with purposive method. The measurement of the exposure factors was done in collaboration with Addis Ababa city Administration and Oromia Bureau of Labour and Social Affair (AACBOLSA). Some measuring instruments were obtained from the Addis Ababa city and Oromia Bureau of Labour and Social Affair.
Data collection methods were focused on the followings basic techniques. These included secondary and primary data collections focusing on both qualitative and quantitative data as defined in the previous section. The data collection mechanisms are devised and prepared with their proper procedures.
Primary data sources are qualitative and quantitative. The qualitative sources are field observation, interview, and informal discussions, while that of quantitative data sources are survey questionnaires and interview questions. The next sections elaborate how the data were obtained from the primary sources.
Observation is an important aspect of science. Observation is tightly connected to data collection, and there are different sources for this: documentation, archival records, interviews, direct observations, and participant observations. Observational research findings are considered strong in validity because the researcher is able to collect a depth of information about a particular behavior. In this dissertation, the researchers used observation method as one tool for collecting information and data before questionnaire design and after the start of research too. The researcher made more than 20 specific observations of manufacturing industries in the study areas. During the observations, it found a deeper understanding of the working environment and the different sections in the production system and OSH practices.
Interview is a loosely structured qualitative in-depth interview with people who are considered to be particularly knowledgeable about the topic of interest. The semi-structured interview is usually conducted in a face-to-face setting which permits the researcher to seek new insights, ask questions, and assess phenomena in different perspectives. It let the researcher to know the in-depth of the present working environment influential factors and consequences. It has provided opportunities for refining data collection efforts and examining specialized systems or processes. It was used when the researcher faces written records or published document limitation or wanted to triangulate the data obtained from other primary and secondary data sources.
This dissertation is also conducted with a qualitative approach and conducting interviews. The advantage of using interviews as a method is that it allows respondents to raise issues that the interviewer may not have expected. All interviews with employees, management, and technicians were conducted by the corresponding researcher, on a face-to-face basis at workplace. All interviews were recorded and transcribed.
The main tool for gaining primary information in practical research is questionnaires, due to the fact that the researcher can decide on the sample and the types of questions to be asked [2].
In this dissertation, each respondent is requested to reply to an identical list of questions mixed so that biasness was prevented. Initially the questionnaire design was coded and mixed up from specific topic based on uniform structures. Consequently, the questionnaire produced valuable data which was required to achieve the dissertation objectives.
The questionnaires developed were based on a five-item Likert scale. Responses were given to each statement using a five-point Likert-type scale, for which 1 = “strongly disagree” to 5 = “strongly agree.” The responses were summed up to produce a score for the measures.
The data was also obtained from the expert’s opinion related to the comparison of the knowledge, management, collaboration, and technology utilization including their sub-factors. The data obtained in this way was used for prioritization and decision-making of OSH, improving factor priority. The prioritization of the factors was using Saaty scales (1–9) and then converting to Fuzzy set values obtained from previous researches using triangular fuzzy set [7].
The researcher has measured the workplace environment for dust, vibration, heat, pressure, light, and noise to know how much is the level of each variable. The primary data sources planned and an actual coverage has been compared as shown in Table 1.
Planned versus actual coverage of the survey.
The response rate for the proposed data source was good, and the pilot test also proved the reliability of questionnaires. Interview/discussion resulted in 87% of responses among the respondents; the survey questionnaire response rate obtained was 71%, and the field observation response rate was 90% for the whole data analysis process. Hence, the data organization quality level has not been compromised.
This response rate is considered to be representative of studies of organizations. As the study agrees on the response rate to be 30%, it is considered acceptable [8]. Saunders et al. [2] argued that the questionnaire with a scale response of 20% response rate is acceptable. Low response rate should not discourage the researchers, because a great deal of published research work also achieves low response rate. Hence, the response rate of this study is acceptable and very good for the purpose of meeting the study objectives.
The pretest for questionnaires, interviews, and tools were conducted to validate that the tool content is valid or not in the sense of the respondents’ understanding. Hence, content validity (in which the questions are answered to the target without excluding important points), internal validity (in which the questions raised answer the outcomes of researchers’ target), and external validity (in which the result can generalize to all the population from the survey sample population) were reflected. It has been proved with this pilot test prior to the start of the basic data collections. Following feedback process, a few minor changes were made to the originally designed data collect tools. The pilot test made for the questionnaire test was on 10 sample sizes selected randomly from the target sectors and experts.
The secondary data refers to data that was collected by someone other than the user. This data source gives insights of the research area of the current state-of-the-art method. It also makes some sort of research gap that needs to be filled by the researcher. This secondary data sources could be internal and external data sources of information that may cover a wide range of areas.
Literature/desk review and industry documents and reports: To achieve the dissertation’s objectives, the researcher has conducted excessive document review and reports of the companies in both online and offline modes. From a methodological point of view, literature reviews can be comprehended as content analysis, where quantitative and qualitative aspects are mixed to assess structural (descriptive) as well as content criteria.
A literature search was conducted using the database sources like MEDLINE; Emerald; Taylor and Francis publications; EMBASE (medical literature); PsycINFO (psychological literature); Sociological Abstracts (sociological literature); accident prevention journals; US Statistics of Labor, European Safety and Health database; ABI Inform; Business Source Premier (business/management literature); EconLit (economic literature); Social Service Abstracts (social work and social service literature); and other related materials. The search strategy was focused on articles or reports that measure one or more of the dimensions within the research OSH model framework. This search strategy was based on a framework and measurement filter strategy developed by the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) group. Based on screening, unrelated articles to the research model and objectives were excluded. Prior to screening, researcher (principal investigator) reviewed a sample of more than 2000 articles, websites, reports, and guidelines to determine whether they should be included for further review or reject. Discrepancies were thoroughly identified and resolved before the review of the main group of more than 300 articles commenced. After excluding the articles based on the title, keywords, and abstract, the remaining articles were reviewed in detail, and the information was extracted on the instrument that was used to assess the dimension of research interest. A complete list of items was then collated within each research targets or objectives and reviewed to identify any missing elements.
Data analysis method follows the procedures listed under the following sections. The data analysis part answered the basic questions raised in the problem statement. The detailed analysis of the developed and developing countries’ experiences on OSH regarding manufacturing industries was analyzed, discussed, compared and contrasted, and synthesized.
Quantitative data were obtained from primary and secondary data discussed above in this chapter. This data analysis was based on their data type using Excel, SPSS 20.0, Office Word format, and other tools. This data analysis focuses on numerical/quantitative data analysis.
Before analysis, data coding of responses and analysis were made. In order to analyze the data obtained easily, the data were coded to SPSS 20.0 software as the data obtained from questionnaires. This task involved identifying, classifying, and assigning a numeric or character symbol to data, which was done in only one way pre-coded [9, 10]. In this study, all of the responses were pre-coded. They were taken from the list of responses, a number of corresponding to a particular selection was given. This process was applied to every earlier question that needed this treatment. Upon completion, the data were then entered to a statistical analysis software package, SPSS version 20.0 on Windows 10 for the next steps.
Under the data analysis, exploration of data has been made with descriptive statistics and graphical analysis. The analysis included exploring the relationship between variables and comparing groups how they affect each other. This has been done using cross tabulation/chi square, correlation, and factor analysis and using nonparametric statistic.
Qualitative data analysis used for triangulation of the quantitative data analysis. The interview, observation, and report records were used to support the findings. The analysis has been incorporated with the quantitative discussion results in the data analysis parts.
The data were entered using SPSS 20.0 on Windows 10 and analyzed. The analysis supported with SPSS software much contributed to the finding. It had contributed to the data validation and correctness of the SPSS results. The software analyzed and compared the results of different variables used in the research questionnaires. Excel is also used to draw the pictures and calculate some analytical solutions.
The reliability of measurements specifies the amount to which it is without bias (error free) and hence ensures consistent measurement across time and across the various items in the instrument [8]. In reliability analysis, it has been checked for the stability and consistency of the data. In the case of reliability analysis, the researcher checked the accuracy and precision of the procedure of measurement. Reliability has numerous definitions and approaches, but in several environments, the concept comes to be consistent [8]. The measurement fulfills the requirements of reliability when it produces consistent results during data analysis procedure. The reliability is determined through Cranach’s alpha as shown in Table 2.
Internal consistency and reliability test of questionnaires items.
K stands for knowledge; M, management; T, technology; C, collaboration; P, policy, standards, and regulation; H, hazards and accident conditions; PPE, personal protective equipment.
Cronbach’s alpha is a measure of internal consistency, i.e., how closely related a set of items are as a group [11]. It is considered to be a measure of scale reliability. The reliability of internal consistency most of the time is measured based on the Cronbach’s alpha value. Reliability coefficient of 0.70 and above is considered “acceptable” in most research situations [12]. In this study, reliability analysis for internal consistency of Likert-scale measurement after deleting 13 items was found similar; the reliability coefficients were found for 76 items were 0.964 and for the individual groupings made shown in Table 2. It was also found internally consistent using the Cronbach’s alpha test. Table 2 shows the internal consistency of the seven major instruments in which their reliability falls in the acceptable range for this research.
Face validity used as defined by Babbie [13] is an indicator that makes it seem a reasonable measure of some variables, and it is the subjective judgment that the instrument measures what it intends to measure in terms of relevance [14]. Thus, the researcher ensured, in this study, when developing the instruments that uncertainties were eliminated by using appropriate words and concepts in order to enhance clarity and general suitability [14]. Furthermore, the researcher submitted the instruments to the research supervisor and the joint supervisor who are both occupational health experts, to ensure validity of the measuring instruments and determine whether the instruments could be considered valid on face value.
In this study, the researcher was guided by reviewed literature related to compliance with the occupational health and safety conditions and data collection methods before he could develop the measuring instruments. In addition, the pretest study that was conducted prior to the main study assisted the researcher to avoid uncertainties of the contents in the data collection measuring instruments. A thorough inspection of the measuring instruments by the statistician and the researcher’s supervisor and joint experts, to ensure that all concepts pertaining to the study were included, ensured that the instruments were enriched.
Insight has been given to the data collectors on how to approach companies, and many of the questionnaires were distributed through MSc students at Addis Ababa Institute of Technology (AAiT) and manufacturing industries’ experience experts. This made the data quality reliable as it has been continually discussed with them. Pretesting for questionnaire was done on 10 workers to assure the quality of the data and for improvement of data collection tools. Supervision during data collection was done to understand how the data collectors are handling the questionnaire, and each filled questionnaires was checked for its completeness, accuracy, clarity, and consistency on a daily basis either face-to-face or by phone/email. The data expected in poor quality were rejected out of the acting during the screening time. Among planned 267 questionnaires, 189 were responded back. Finally, it was analyzed by the principal investigator.
The data were collected from the company representative with the knowledge of OSH. Articles written in English and Amharic were included in this study. Database information obtained in relation to articles and those who have OSH area such as interventions method, method of accident identification, impact of occupational accidents, types of occupational injuries/disease, and impact of occupational accidents, and disease on productivity and costs of company and have used at least one form of feedback mechanism. No specific time period was chosen in order to access all available published papers. The questionnaire statements which are similar in the questionnaire have been rejected from the data analysis.
Ethical clearance was obtained from the School of Mechanical and Industrial Engineering, Institute of Technology, Addis Ababa University. Official letters were written from the School of Mechanical and Industrial Engineering to the respective manufacturing industries. The purpose of the study was explained to the study subjects. The study subjects were told that the information they provided was kept confidential and that their identities would not be revealed in association with the information they provided. Informed consent was secured from each participant. For bad working environment assessment findings, feedback will be given to all manufacturing industries involved in the study. There is a plan to give a copy of the result to the respective study manufacturing industries’ and ministries’ offices. The respondents’ privacy and their responses were not individually analyzed and included in the report.
The result of this study will be presented to the Addis Ababa University, AAiT, School of Mechanical and Industrial Engineering. It will also be communicated to the Ethiopian manufacturing industries, Ministry of Labor and Social Affair, Ministry of Industry, and Ministry of Health from where the data was collected. The result will also be availed by publication and online presentation in Google Scholars. To this end, about five articles were published and disseminated to the whole world.
The research methodology and design indicated overall process of the flow of the research for the given study. The data sources and data collection methods were used. The overall research strategies and framework are indicated in this research process from problem formulation to problem validation including all the parameters. It has laid some foundation and how research methodology is devised and framed for researchers. This means, it helps researchers to consider it as one of the samples and models for the research data collection and process from the beginning of the problem statement to the research finding. Especially, this research flow helps new researchers to the research environment and methodology in particular.
There is no “conflict of interest.”
IntechOpen's Authorship Policy is based on ICMJE criteria for authorship. An Author, one must:
',metaTitle:"Authorship Policy",metaDescription:"IN TECH's Authorship Policy is based on ICMJE criteria for authorship. In order to be identified as an Author, one must:",metaKeywords:null,canonicalURL:"/page/authorship-policy",contentRaw:'[{"type":"htmlEditorComponent","content":"All contributors who meet these criteria are listed as Authors. Their exact contributions should be described in the manuscript at the time of submission.
\\n\\nConversely, all contributors who do not meet these criteria should be listed in the Acknowledgments section of the manuscript, along with a short description of their specific contributions.
\\n\\nCHANGES IN AUTHORSHIP
\\n\\nIf it is felt necessary to make changes to the list of Authors after a manuscript has been submitted or published, it is the responsibility of the Author concerned to provide a valid reason to amend the published list. Additionally, all listed Authors must verify and approve the proposed changes in order for any amendments to be made.
\\n\\nAFFILIATION
\\n\\nAuthors are responsible for ensuring all addresses and emails provided are correct. Under affiliation(s) all Authors should indicate where the research was conducted. Please note that no changes to the affiliation(s) can be made after the chapter has been published.
\\n\\nPolicy last updated: 2017-05-29
\\n"}]'},components:[{type:"htmlEditorComponent",content:"All contributors who meet these criteria are listed as Authors. Their exact contributions should be described in the manuscript at the time of submission.
\n\nConversely, all contributors who do not meet these criteria should be listed in the Acknowledgments section of the manuscript, along with a short description of their specific contributions.
\n\nCHANGES IN AUTHORSHIP
\n\nIf it is felt necessary to make changes to the list of Authors after a manuscript has been submitted or published, it is the responsibility of the Author concerned to provide a valid reason to amend the published list. Additionally, all listed Authors must verify and approve the proposed changes in order for any amendments to be made.
\n\nAFFILIATION
\n\nAuthors are responsible for ensuring all addresses and emails provided are correct. Under affiliation(s) all Authors should indicate where the research was conducted. Please note that no changes to the affiliation(s) can be made after the chapter has been published.
\n\nPolicy last updated: 2017-05-29
\n"}]},successStories:{items:[]},authorsAndEditors:{filterParams:{sort:"featured,name"},profiles:[{id:"6700",title:"Dr.",name:"Abbass A.",middleName:null,surname:"Hashim",slug:"abbass-a.-hashim",fullName:"Abbass A. Hashim",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/6700/images/1864_n.jpg",biography:"Currently I am carrying out research in several areas of interest, mainly covering work on chemical and bio-sensors, semiconductor thin film device fabrication and characterisation.\nAt the moment I have very strong interest in radiation environmental pollution and bacteriology treatment. The teams of researchers are working very hard to bring novel results in this field. I am also a member of the team in charge for the supervision of Ph.D. students in the fields of development of silicon based planar waveguide sensor devices, study of inelastic electron tunnelling in planar tunnelling nanostructures for sensing applications and development of organotellurium(IV) compounds for semiconductor applications. I am a specialist in data analysis techniques and nanosurface structure. I have served as the editor for many books, been a member of the editorial board in science journals, have published many papers and hold many patents.",institutionString:null,institution:{name:"Sheffield Hallam University",country:{name:"United Kingdom"}}},{id:"54525",title:"Prof.",name:"Abdul Latif",middleName:null,surname:"Ahmad",slug:"abdul-latif-ahmad",fullName:"Abdul Latif Ahmad",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"20567",title:"Prof.",name:"Ado",middleName:null,surname:"Jorio",slug:"ado-jorio",fullName:"Ado Jorio",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Universidade Federal de Minas Gerais",country:{name:"Brazil"}}},{id:"47940",title:"Dr.",name:"Alberto",middleName:null,surname:"Mantovani",slug:"alberto-mantovani",fullName:"Alberto Mantovani",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"12392",title:"Mr.",name:"Alex",middleName:null,surname:"Lazinica",slug:"alex-lazinica",fullName:"Alex Lazinica",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/12392/images/7282_n.png",biography:"Alex Lazinica is the founder and CEO of IntechOpen. After obtaining a Master's degree in Mechanical Engineering, he continued his PhD studies in Robotics at the Vienna University of Technology. Here he worked as a robotic researcher with the university's Intelligent Manufacturing Systems Group as well as a guest researcher at various European universities, including the Swiss Federal Institute of Technology Lausanne (EPFL). During this time he published more than 20 scientific papers, gave presentations, served as a reviewer for major robotic journals and conferences and most importantly he co-founded and built the International Journal of Advanced Robotic Systems- world's first Open Access journal in the field of robotics. Starting this journal was a pivotal point in his career, since it was a pathway to founding IntechOpen - Open Access publisher focused on addressing academic researchers needs. Alex is a personification of IntechOpen key values being trusted, open and entrepreneurial. Today his focus is on defining the growth and development strategy for the company.",institutionString:null,institution:{name:"TU Wien",country:{name:"Austria"}}},{id:"19816",title:"Prof.",name:"Alexander",middleName:null,surname:"Kokorin",slug:"alexander-kokorin",fullName:"Alexander Kokorin",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/19816/images/1607_n.jpg",biography:"Alexander I. Kokorin: born: 1947, Moscow; DSc., PhD; Principal Research Fellow (Research Professor) of Department of Kinetics and Catalysis, N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow.\r\nArea of research interests: physical chemistry of complex-organized molecular and nanosized systems, including polymer-metal complexes; the surface of doped oxide semiconductors. He is an expert in structural, absorptive, catalytic and photocatalytic properties, in structural organization and dynamic features of ionic liquids, in magnetic interactions between paramagnetic centers. The author or co-author of 3 books, over 200 articles and reviews in scientific journals and books. He is an actual member of the International EPR/ESR Society, European Society on Quantum Solar Energy Conversion, Moscow House of Scientists, of the Board of Moscow Physical Society.",institutionString:null,institution:{name:"Semenov Institute of Chemical Physics",country:{name:"Russia"}}},{id:"62389",title:"PhD.",name:"Ali Demir",middleName:null,surname:"Sezer",slug:"ali-demir-sezer",fullName:"Ali Demir Sezer",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/62389/images/3413_n.jpg",biography:"Dr. Ali Demir Sezer has a Ph.D. from Pharmaceutical Biotechnology at the Faculty of Pharmacy, University of Marmara (Turkey). He is the member of many Pharmaceutical Associations and acts as a reviewer of scientific journals and European projects under different research areas such as: drug delivery systems, nanotechnology and pharmaceutical biotechnology. Dr. Sezer is the author of many scientific publications in peer-reviewed journals and poster communications. Focus of his research activity is drug delivery, physico-chemical characterization and biological evaluation of biopolymers micro and nanoparticles as modified drug delivery system, and colloidal drug carriers (liposomes, nanoparticles etc.).",institutionString:null,institution:{name:"Marmara University",country:{name:"Turkey"}}},{id:"61051",title:"Prof.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:null},{id:"100762",title:"Prof.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"St David's Medical Center",country:{name:"United States of America"}}},{id:"107416",title:"Dr.",name:"Andrea",middleName:null,surname:"Natale",slug:"andrea-natale",fullName:"Andrea Natale",position:null,profilePictureURL:"//cdnintech.com/web/frontend/www/assets/author.svg",biography:null,institutionString:null,institution:{name:"Texas Cardiac Arrhythmia",country:{name:"United States of America"}}},{id:"64434",title:"Dr.",name:"Angkoon",middleName:null,surname:"Phinyomark",slug:"angkoon-phinyomark",fullName:"Angkoon Phinyomark",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/64434/images/2619_n.jpg",biography:"My name is Angkoon Phinyomark. I received a B.Eng. degree in Computer Engineering with First Class Honors in 2008 from Prince of Songkla University, Songkhla, Thailand, where I received a Ph.D. degree in Electrical Engineering. My research interests are primarily in the area of biomedical signal processing and classification notably EMG (electromyography signal), EOG (electrooculography signal), and EEG (electroencephalography signal), image analysis notably breast cancer analysis and optical coherence tomography, and rehabilitation engineering. I became a student member of IEEE in 2008. During October 2011-March 2012, I had worked at School of Computer Science and Electronic Engineering, University of Essex, Colchester, Essex, United Kingdom. In addition, during a B.Eng. I had been a visiting research student at Faculty of Computer Science, University of Murcia, Murcia, Spain for three months.\n\nI have published over 40 papers during 5 years in refereed journals, books, and conference proceedings in the areas of electro-physiological signals processing and classification, notably EMG and EOG signals, fractal analysis, wavelet analysis, texture analysis, feature extraction and machine learning algorithms, and assistive and rehabilitative devices. I have several computer programming language certificates, i.e. Sun Certified Programmer for the Java 2 Platform 1.4 (SCJP), Microsoft Certified Professional Developer, Web Developer (MCPD), Microsoft Certified Technology Specialist, .NET Framework 2.0 Web (MCTS). I am a Reviewer for several refereed journals and international conferences, such as IEEE Transactions on Biomedical Engineering, IEEE Transactions on Industrial Electronics, Optic Letters, Measurement Science Review, and also a member of the International Advisory Committee for 2012 IEEE Business Engineering and Industrial Applications and 2012 IEEE Symposium on Business, Engineering and Industrial Applications.",institutionString:null,institution:{name:"Joseph Fourier University",country:{name:"France"}}},{id:"55578",title:"Dr.",name:"Antonio",middleName:null,surname:"Jurado-Navas",slug:"antonio-jurado-navas",fullName:"Antonio Jurado-Navas",position:null,profilePictureURL:"https://mts.intechopen.com/storage/users/55578/images/4574_n.png",biography:"Antonio Jurado-Navas received the M.S. degree (2002) and the Ph.D. degree (2009) in Telecommunication Engineering, both from the University of Málaga (Spain). He first worked as a consultant at Vodafone-Spain. From 2004 to 2011, he was a Research Assistant with the Communications Engineering Department at the University of Málaga. In 2011, he became an Assistant Professor in the same department. From 2012 to 2015, he was with Ericsson Spain, where he was working on geo-location\ntools for third generation mobile networks. Since 2015, he is a Marie-Curie fellow at the Denmark Technical University. His current research interests include the areas of mobile communication systems and channel modeling in addition to atmospheric optical communications, adaptive optics and statistics",institutionString:null,institution:{name:"University of Malaga",country:{name:"Spain"}}}],filtersByRegion:[{group:"region",caption:"North America",value:1,count:5698},{group:"region",caption:"Middle and South America",value:2,count:5172},{group:"region",caption:"Africa",value:3,count:1689},{group:"region",caption:"Asia",value:4,count:10243},{group:"region",caption:"Australia and Oceania",value:5,count:888},{group:"region",caption:"Europe",value:6,count:15647}],offset:12,limit:12,total:117315},chapterEmbeded:{data:{}},editorApplication:{success:null,errors:{}},ofsBooks:{filterParams:{sort:"dateendthirdsteppublish"},books:[],filtersByTopic:[{group:"topic",caption:"Agricultural and Biological Sciences",value:5,count:9},{group:"topic",caption:"Biochemistry, Genetics and Molecular Biology",value:6,count:18},{group:"topic",caption:"Business, Management and Economics",value:7,count:2},{group:"topic",caption:"Chemistry",value:8,count:7},{group:"topic",caption:"Computer and Information Science",value:9,count:11},{group:"topic",caption:"Earth and Planetary Sciences",value:10,count:5},{group:"topic",caption:"Engineering",value:11,count:15},{group:"topic",caption:"Environmental Sciences",value:12,count:2},{group:"topic",caption:"Immunology and Microbiology",value:13,count:5},{group:"topic",caption:"Materials Science",value:14,count:4},{group:"topic",caption:"Mathematics",value:15,count:1},{group:"topic",caption:"Medicine",value:16,count:62},{group:"topic",caption:"Nanotechnology and Nanomaterials",value:17,count:1},{group:"topic",caption:"Neuroscience",value:18,count:1},{group:"topic",caption:"Pharmacology, Toxicology and Pharmaceutical Science",value:19,count:6},{group:"topic",caption:"Physics",value:20,count:2},{group:"topic",caption:"Psychology",value:21,count:3},{group:"topic",caption:"Robotics",value:22,count:1},{group:"topic",caption:"Social Sciences",value:23,count:3},{group:"topic",caption:"Technology",value:24,count:1},{group:"topic",caption:"Veterinary Medicine and Science",value:25,count:2}],offset:0,limit:12,total:null},popularBooks:{featuredBooks:[{type:"book",id:"7802",title:"Modern Slavery and Human Trafficking",subtitle:null,isOpenForSubmission:!1,hash:"587a0b7fb765f31cc98de33c6c07c2e0",slug:"modern-slavery-and-human-trafficking",bookSignature:"Jane Reeves",coverURL:"https://cdn.intechopen.com/books/images_new/7802.jpg",editors:[{id:"211328",title:"Prof.",name:"Jane",middleName:null,surname:"Reeves",slug:"jane-reeves",fullName:"Jane Reeves"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8545",title:"Animal Reproduction in Veterinary Medicine",subtitle:null,isOpenForSubmission:!1,hash:"13aaddf5fdbbc78387e77a7da2388bf6",slug:"animal-reproduction-in-veterinary-medicine",bookSignature:"Faruk Aral, Rita Payan-Carreira and Miguel Quaresma",coverURL:"https://cdn.intechopen.com/books/images_new/8545.jpg",editors:[{id:"25600",title:"Prof.",name:"Faruk",middleName:null,surname:"Aral",slug:"faruk-aral",fullName:"Faruk Aral"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9961",title:"Data Mining",subtitle:"Methods, Applications and Systems",isOpenForSubmission:!1,hash:"ed79fb6364f2caf464079f94a0387146",slug:"data-mining-methods-applications-and-systems",bookSignature:"Derya Birant",coverURL:"https://cdn.intechopen.com/books/images_new/9961.jpg",editors:[{id:"15609",title:"Dr.",name:"Derya",middleName:null,surname:"Birant",slug:"derya-birant",fullName:"Derya Birant"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9157",title:"Neurodegenerative Diseases",subtitle:"Molecular Mechanisms and Current Therapeutic Approaches",isOpenForSubmission:!1,hash:"bc8be577966ef88735677d7e1e92ed28",slug:"neurodegenerative-diseases-molecular-mechanisms-and-current-therapeutic-approaches",bookSignature:"Nagehan Ersoy Tunalı",coverURL:"https://cdn.intechopen.com/books/images_new/9157.jpg",editors:[{id:"82778",title:"Ph.D.",name:"Nagehan",middleName:null,surname:"Ersoy Tunalı",slug:"nagehan-ersoy-tunali",fullName:"Nagehan Ersoy Tunalı"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8686",title:"Direct Torque Control Strategies of Electrical Machines",subtitle:null,isOpenForSubmission:!1,hash:"b6ad22b14db2b8450228545d3d4f6b1a",slug:"direct-torque-control-strategies-of-electrical-machines",bookSignature:"Fatma Ben Salem",coverURL:"https://cdn.intechopen.com/books/images_new/8686.jpg",editors:[{id:"295623",title:"Associate Prof.",name:"Fatma",middleName:null,surname:"Ben Salem",slug:"fatma-ben-salem",fullName:"Fatma Ben Salem"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7434",title:"Molecular Biotechnology",subtitle:null,isOpenForSubmission:!1,hash:"eceede809920e1ec7ecadd4691ede2ec",slug:"molecular-biotechnology",bookSignature:"Sergey Sedykh",coverURL:"https://cdn.intechopen.com/books/images_new/7434.jpg",editors:[{id:"178316",title:"Ph.D.",name:"Sergey",middleName:null,surname:"Sedykh",slug:"sergey-sedykh",fullName:"Sergey Sedykh"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9839",title:"Outdoor Recreation",subtitle:"Physiological and Psychological Effects on Health",isOpenForSubmission:!1,hash:"5f5a0d64267e32567daffa5b0c6a6972",slug:"outdoor-recreation-physiological-and-psychological-effects-on-health",bookSignature:"Hilde G. Nielsen",coverURL:"https://cdn.intechopen.com/books/images_new/9839.jpg",editors:[{id:"158692",title:"Ph.D.",name:"Hilde G.",middleName:null,surname:"Nielsen",slug:"hilde-g.-nielsen",fullName:"Hilde G. Nielsen"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9208",title:"Welding",subtitle:"Modern Topics",isOpenForSubmission:!1,hash:"7d6be076ccf3a3f8bd2ca52d86d4506b",slug:"welding-modern-topics",bookSignature:"Sadek Crisóstomo Absi Alfaro, Wojciech Borek and Błażej Tomiczek",coverURL:"https://cdn.intechopen.com/books/images_new/9208.jpg",editors:[{id:"65292",title:"Prof.",name:"Sadek Crisostomo Absi",middleName:"C. Absi",surname:"Alfaro",slug:"sadek-crisostomo-absi-alfaro",fullName:"Sadek Crisostomo Absi Alfaro"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9139",title:"Topics in Primary Care Medicine",subtitle:null,isOpenForSubmission:!1,hash:"ea774a4d4c1179da92a782e0ae9cde92",slug:"topics-in-primary-care-medicine",bookSignature:"Thomas F. Heston",coverURL:"https://cdn.intechopen.com/books/images_new/9139.jpg",editors:[{id:"217926",title:"Dr.",name:"Thomas F.",middleName:null,surname:"Heston",slug:"thomas-f.-heston",fullName:"Thomas F. Heston"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9343",title:"Trace Metals in the Environment",subtitle:"New Approaches and Recent Advances",isOpenForSubmission:!1,hash:"ae07e345bc2ce1ebbda9f70c5cd12141",slug:"trace-metals-in-the-environment-new-approaches-and-recent-advances",bookSignature:"Mario Alfonso Murillo-Tovar, Hugo Saldarriaga-Noreña and Agnieszka Saeid",coverURL:"https://cdn.intechopen.com/books/images_new/9343.jpg",editors:[{id:"255959",title:"Dr.",name:"Mario Alfonso",middleName:null,surname:"Murillo-Tovar",slug:"mario-alfonso-murillo-tovar",fullName:"Mario Alfonso Murillo-Tovar"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8697",title:"Virtual Reality and Its Application in Education",subtitle:null,isOpenForSubmission:!1,hash:"ee01b5e387ba0062c6b0d1e9227bda05",slug:"virtual-reality-and-its-application-in-education",bookSignature:"Dragan Cvetković",coverURL:"https://cdn.intechopen.com/books/images_new/8697.jpg",editors:[{id:"101330",title:"Dr.",name:"Dragan",middleName:"Mladen",surname:"Cvetković",slug:"dragan-cvetkovic",fullName:"Dragan Cvetković"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7831",title:"Sustainability in Urban Planning and Design",subtitle:null,isOpenForSubmission:!1,hash:"c924420492c8c2c9751e178d025f4066",slug:"sustainability-in-urban-planning-and-design",bookSignature:"Amjad Almusaed, Asaad Almssad and Linh Truong - Hong",coverURL:"https://cdn.intechopen.com/books/images_new/7831.jpg",editors:[{id:"110471",title:"Dr.",name:"Amjad",middleName:"Zaki",surname:"Almusaed",slug:"amjad-almusaed",fullName:"Amjad Almusaed"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:12,limit:12,total:5141},hotBookTopics:{hotBooks:[],offset:0,limit:12,total:null},publish:{},publishingProposal:{success:null,errors:{}},books:{featuredBooks:[{type:"book",id:"9208",title:"Welding",subtitle:"Modern Topics",isOpenForSubmission:!1,hash:"7d6be076ccf3a3f8bd2ca52d86d4506b",slug:"welding-modern-topics",bookSignature:"Sadek Crisóstomo Absi Alfaro, Wojciech Borek and Błażej Tomiczek",coverURL:"https://cdn.intechopen.com/books/images_new/9208.jpg",editors:[{id:"65292",title:"Prof.",name:"Sadek Crisostomo Absi",middleName:"C. Absi",surname:"Alfaro",slug:"sadek-crisostomo-absi-alfaro",fullName:"Sadek Crisostomo Absi Alfaro"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9139",title:"Topics in Primary Care Medicine",subtitle:null,isOpenForSubmission:!1,hash:"ea774a4d4c1179da92a782e0ae9cde92",slug:"topics-in-primary-care-medicine",bookSignature:"Thomas F. Heston",coverURL:"https://cdn.intechopen.com/books/images_new/9139.jpg",editors:[{id:"217926",title:"Dr.",name:"Thomas F.",middleName:null,surname:"Heston",slug:"thomas-f.-heston",fullName:"Thomas F. Heston"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"8697",title:"Virtual Reality and Its Application in Education",subtitle:null,isOpenForSubmission:!1,hash:"ee01b5e387ba0062c6b0d1e9227bda05",slug:"virtual-reality-and-its-application-in-education",bookSignature:"Dragan Cvetković",coverURL:"https://cdn.intechopen.com/books/images_new/8697.jpg",editors:[{id:"101330",title:"Dr.",name:"Dragan",middleName:"Mladen",surname:"Cvetković",slug:"dragan-cvetkovic",fullName:"Dragan Cvetković"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9343",title:"Trace Metals in the Environment",subtitle:"New Approaches and Recent Advances",isOpenForSubmission:!1,hash:"ae07e345bc2ce1ebbda9f70c5cd12141",slug:"trace-metals-in-the-environment-new-approaches-and-recent-advances",bookSignature:"Mario Alfonso Murillo-Tovar, Hugo Saldarriaga-Noreña and Agnieszka Saeid",coverURL:"https://cdn.intechopen.com/books/images_new/9343.jpg",editors:[{id:"255959",title:"Dr.",name:"Mario Alfonso",middleName:null,surname:"Murillo-Tovar",slug:"mario-alfonso-murillo-tovar",fullName:"Mario Alfonso Murillo-Tovar"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9785",title:"Endometriosis",subtitle:null,isOpenForSubmission:!1,hash:"f457ca61f29cf7e8bc191732c50bb0ce",slug:"endometriosis",bookSignature:"Courtney Marsh",coverURL:"https://cdn.intechopen.com/books/images_new/9785.jpg",editors:[{id:"255491",title:"Dr.",name:"Courtney",middleName:null,surname:"Marsh",slug:"courtney-marsh",fullName:"Courtney Marsh"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7831",title:"Sustainability in Urban Planning and Design",subtitle:null,isOpenForSubmission:!1,hash:"c924420492c8c2c9751e178d025f4066",slug:"sustainability-in-urban-planning-and-design",bookSignature:"Amjad Almusaed, Asaad Almssad and Linh Truong - Hong",coverURL:"https://cdn.intechopen.com/books/images_new/7831.jpg",editors:[{id:"110471",title:"Dr.",name:"Amjad",middleName:"Zaki",surname:"Almusaed",slug:"amjad-almusaed",fullName:"Amjad Almusaed"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9376",title:"Contemporary Developments and Perspectives in International Health Security",subtitle:"Volume 1",isOpenForSubmission:!1,hash:"b9a00b84cd04aae458fb1d6c65795601",slug:"contemporary-developments-and-perspectives-in-international-health-security-volume-1",bookSignature:"Stanislaw P. Stawicki, Michael S. Firstenberg, Sagar C. Galwankar, Ricardo Izurieta and Thomas Papadimos",coverURL:"https://cdn.intechopen.com/books/images_new/9376.jpg",editors:[{id:"181694",title:"Dr.",name:"Stanislaw P.",middleName:null,surname:"Stawicki",slug:"stanislaw-p.-stawicki",fullName:"Stanislaw P. Stawicki"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7769",title:"Medical Isotopes",subtitle:null,isOpenForSubmission:!1,hash:"f8d3c5a6c9a42398e56b4e82264753f7",slug:"medical-isotopes",bookSignature:"Syed Ali Raza Naqvi and Muhammad Babar Imrani",coverURL:"https://cdn.intechopen.com/books/images_new/7769.jpg",editors:[{id:"259190",title:"Dr.",name:"Syed Ali Raza",middleName:null,surname:"Naqvi",slug:"syed-ali-raza-naqvi",fullName:"Syed Ali Raza Naqvi"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"9279",title:"Concepts, Applications and Emerging Opportunities in Industrial Engineering",subtitle:null,isOpenForSubmission:!1,hash:"9bfa87f9b627a5468b7c1e30b0eea07a",slug:"concepts-applications-and-emerging-opportunities-in-industrial-engineering",bookSignature:"Gary Moynihan",coverURL:"https://cdn.intechopen.com/books/images_new/9279.jpg",editors:[{id:"16974",title:"Dr.",name:"Gary",middleName:null,surname:"Moynihan",slug:"gary-moynihan",fullName:"Gary Moynihan"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}},{type:"book",id:"7807",title:"A Closer Look at Organizational Culture in Action",subtitle:null,isOpenForSubmission:!1,hash:"05c608b9271cc2bc711f4b28748b247b",slug:"a-closer-look-at-organizational-culture-in-action",bookSignature:"Süleyman Davut Göker",coverURL:"https://cdn.intechopen.com/books/images_new/7807.jpg",editors:[{id:"190035",title:"Associate Prof.",name:"Süleyman Davut",middleName:null,surname:"Göker",slug:"suleyman-davut-goker",fullName:"Süleyman Davut Göker"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],latestBooks:[{type:"book",id:"7434",title:"Molecular Biotechnology",subtitle:null,isOpenForSubmission:!1,hash:"eceede809920e1ec7ecadd4691ede2ec",slug:"molecular-biotechnology",bookSignature:"Sergey Sedykh",coverURL:"https://cdn.intechopen.com/books/images_new/7434.jpg",editedByType:"Edited by",editors:[{id:"178316",title:"Ph.D.",name:"Sergey",middleName:null,surname:"Sedykh",slug:"sergey-sedykh",fullName:"Sergey Sedykh"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8545",title:"Animal Reproduction in Veterinary Medicine",subtitle:null,isOpenForSubmission:!1,hash:"13aaddf5fdbbc78387e77a7da2388bf6",slug:"animal-reproduction-in-veterinary-medicine",bookSignature:"Faruk Aral, Rita Payan-Carreira and Miguel Quaresma",coverURL:"https://cdn.intechopen.com/books/images_new/8545.jpg",editedByType:"Edited by",editors:[{id:"25600",title:"Prof.",name:"Faruk",middleName:null,surname:"Aral",slug:"faruk-aral",fullName:"Faruk Aral"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9569",title:"Methods in Molecular Medicine",subtitle:null,isOpenForSubmission:!1,hash:"691d3f3c4ac25a8093414e9b270d2843",slug:"methods-in-molecular-medicine",bookSignature:"Yusuf Tutar",coverURL:"https://cdn.intechopen.com/books/images_new/9569.jpg",editedByType:"Edited by",editors:[{id:"158492",title:"Prof.",name:"Yusuf",middleName:null,surname:"Tutar",slug:"yusuf-tutar",fullName:"Yusuf Tutar"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9839",title:"Outdoor Recreation",subtitle:"Physiological and Psychological Effects on Health",isOpenForSubmission:!1,hash:"5f5a0d64267e32567daffa5b0c6a6972",slug:"outdoor-recreation-physiological-and-psychological-effects-on-health",bookSignature:"Hilde G. Nielsen",coverURL:"https://cdn.intechopen.com/books/images_new/9839.jpg",editedByType:"Edited by",editors:[{id:"158692",title:"Ph.D.",name:"Hilde G.",middleName:null,surname:"Nielsen",slug:"hilde-g.-nielsen",fullName:"Hilde G. Nielsen"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7802",title:"Modern Slavery and Human Trafficking",subtitle:null,isOpenForSubmission:!1,hash:"587a0b7fb765f31cc98de33c6c07c2e0",slug:"modern-slavery-and-human-trafficking",bookSignature:"Jane Reeves",coverURL:"https://cdn.intechopen.com/books/images_new/7802.jpg",editedByType:"Edited by",editors:[{id:"211328",title:"Prof.",name:"Jane",middleName:null,surname:"Reeves",slug:"jane-reeves",fullName:"Jane Reeves"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8063",title:"Food Security in Africa",subtitle:null,isOpenForSubmission:!1,hash:"8cbf3d662b104d19db2efc9d59249efc",slug:"food-security-in-africa",bookSignature:"Barakat Mahmoud",coverURL:"https://cdn.intechopen.com/books/images_new/8063.jpg",editedByType:"Edited by",editors:[{id:"92016",title:"Dr.",name:"Barakat",middleName:null,surname:"Mahmoud",slug:"barakat-mahmoud",fullName:"Barakat Mahmoud"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"10118",title:"Plant Stress Physiology",subtitle:null,isOpenForSubmission:!1,hash:"c68b09d2d2634fc719ae3b9a64a27839",slug:"plant-stress-physiology",bookSignature:"Akbar Hossain",coverURL:"https://cdn.intechopen.com/books/images_new/10118.jpg",editedByType:"Edited by",editors:[{id:"280755",title:"Dr.",name:"Akbar",middleName:null,surname:"Hossain",slug:"akbar-hossain",fullName:"Akbar Hossain"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9157",title:"Neurodegenerative Diseases",subtitle:"Molecular Mechanisms and Current Therapeutic Approaches",isOpenForSubmission:!1,hash:"bc8be577966ef88735677d7e1e92ed28",slug:"neurodegenerative-diseases-molecular-mechanisms-and-current-therapeutic-approaches",bookSignature:"Nagehan Ersoy Tunalı",coverURL:"https://cdn.intechopen.com/books/images_new/9157.jpg",editedByType:"Edited by",editors:[{id:"82778",title:"Ph.D.",name:"Nagehan",middleName:null,surname:"Ersoy Tunalı",slug:"nagehan-ersoy-tunali",fullName:"Nagehan Ersoy Tunalı"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"9961",title:"Data Mining",subtitle:"Methods, Applications and Systems",isOpenForSubmission:!1,hash:"ed79fb6364f2caf464079f94a0387146",slug:"data-mining-methods-applications-and-systems",bookSignature:"Derya Birant",coverURL:"https://cdn.intechopen.com/books/images_new/9961.jpg",editedByType:"Edited by",editors:[{id:"15609",title:"Dr.",name:"Derya",middleName:null,surname:"Birant",slug:"derya-birant",fullName:"Derya Birant"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8686",title:"Direct Torque Control Strategies of Electrical Machines",subtitle:null,isOpenForSubmission:!1,hash:"b6ad22b14db2b8450228545d3d4f6b1a",slug:"direct-torque-control-strategies-of-electrical-machines",bookSignature:"Fatma Ben Salem",coverURL:"https://cdn.intechopen.com/books/images_new/8686.jpg",editedByType:"Edited by",editors:[{id:"295623",title:"Associate Prof.",name:"Fatma",middleName:null,surname:"Ben Salem",slug:"fatma-ben-salem",fullName:"Fatma Ben Salem"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}]},subject:{topic:{id:"113",title:"Chemical Engineering",slug:"engineering-chemical-engineering",parent:{title:"Engineering",slug:"engineering"},numberOfBooks:38,numberOfAuthorsAndEditors:1203,numberOfWosCitations:1892,numberOfCrossrefCitations:936,numberOfDimensionsCitations:2487,videoUrl:null,fallbackUrl:null,description:null},booksByTopicFilter:{topicSlug:"engineering-chemical-engineering",sort:"-publishedDate",limit:12,offset:0},booksByTopicCollection:[{type:"book",id:"7353",title:"Paraffin",subtitle:"an Overview",isOpenForSubmission:!1,hash:"37902d2ff0f7e495b628ab41622be6e4",slug:"paraffin-an-overview",bookSignature:"Fathi Samir Soliman",coverURL:"https://cdn.intechopen.com/books/images_new/7353.jpg",editedByType:"Edited by",editors:[{id:"270842",title:"Dr.",name:"Fathi Samir",middleName:null,surname:"Soliman",slug:"fathi-samir-soliman",fullName:"Fathi Samir Soliman"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7323",title:"Processing of Heavy Crude Oils",subtitle:"Challenges and Opportunities",isOpenForSubmission:!1,hash:"a019fb5c826a5049700528cfc505f0db",slug:"processing-of-heavy-crude-oils-challenges-and-opportunities",bookSignature:"Ramasamy Marappa Gounder",coverURL:"https://cdn.intechopen.com/books/images_new/7323.jpg",editedByType:"Edited by",editors:[{id:"209620",title:"Dr.",name:"Ramasamy",middleName:null,surname:"Marappa Gounder",slug:"ramasamy-marappa-gounder",fullName:"Ramasamy Marappa Gounder"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"8448",title:"Glycerine Production and Transformation",subtitle:"An Innovative Platform for Sustainable Biorefinery and Energy",isOpenForSubmission:!1,hash:"63834d3e01c2550240908758fb0fbe34",slug:"glycerine-production-and-transformation-an-innovative-platform-for-sustainable-biorefinery-and-energy",bookSignature:"Marco Frediani, Mattia Bartoli and Luca Rosi",coverURL:"https://cdn.intechopen.com/books/images_new/8448.jpg",editedByType:"Edited by",editors:[{id:"53209",title:"Dr.",name:"Marco",middleName:null,surname:"Frediani",slug:"marco-frediani",fullName:"Marco Frediani"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6829",title:"Petroleum Chemicals",subtitle:"Recent Insight",isOpenForSubmission:!1,hash:"058919afbb548d3448e70238b4637e84",slug:"petroleum-chemicals-recent-insight",bookSignature:"Mansoor Zoveidavianpoor",coverURL:"https://cdn.intechopen.com/books/images_new/6829.jpg",editedByType:"Edited by",editors:[{id:"92105",title:"Dr.",name:"Mansoor",middleName:null,surname:"Zoveidavianpoor",slug:"mansoor-zoveidavianpoor",fullName:"Mansoor Zoveidavianpoor"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6770",title:"Laboratory Unit Operations and Experimental Methods in Chemical Engineering",subtitle:null,isOpenForSubmission:!1,hash:"a139364b1ca4b347f2321a0430079830",slug:"laboratory-unit-operations-and-experimental-methods-in-chemical-engineering",bookSignature:"Omar M. Basha and Badie I. Morsi",coverURL:"https://cdn.intechopen.com/books/images_new/6770.jpg",editedByType:"Edited by",editors:[{id:"174770",title:"Dr.",name:"Omar M.",middleName:null,surname:"Basha",slug:"omar-m.-basha",fullName:"Omar M. Basha"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"7230",title:"Recent Advances in Ionic Liquids",subtitle:null,isOpenForSubmission:!1,hash:"cebbba5d7b2b6c41fafebde32f87f90b",slug:"recent-advances-in-ionic-liquids",bookSignature:"Mohammed Muzibur Rahman",coverURL:"https://cdn.intechopen.com/books/images_new/7230.jpg",editedByType:"Edited by",editors:[{id:"24438",title:"Prof.",name:"Mohammed Muzibur",middleName:null,surname:"Rahman",slug:"mohammed-muzibur-rahman",fullName:"Mohammed Muzibur Rahman"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6186",title:"Carbon Dioxide Chemistry, Capture and Oil Recovery",subtitle:null,isOpenForSubmission:!1,hash:"720a601cd2b5476cbeb817906a4ab2dd",slug:"carbon-dioxide-chemistry-capture-and-oil-recovery",bookSignature:"Iyad Karamé, Janah Shaya and Hassan Srour",coverURL:"https://cdn.intechopen.com/books/images_new/6186.jpg",editedByType:"Edited by",editors:[{id:"145512",title:"Prof.",name:"Iyad",middleName:null,surname:"Karamé",slug:"iyad-karame",fullName:"Iyad Karamé"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6730",title:"Palm Oil",subtitle:null,isOpenForSubmission:!1,hash:"96d058f3abbc8d0660dcd56042a8ece8",slug:"palm-oil",bookSignature:"Viduranga Waisundara",coverURL:"https://cdn.intechopen.com/books/images_new/6730.jpg",editedByType:"Edited by",editors:[{id:"194281",title:"Dr.",name:"Viduranga Yashasvi",middleName:null,surname:"Waisundara",slug:"viduranga-yashasvi-waisundara",fullName:"Viduranga Yashasvi Waisundara"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"6631",title:"Heat Transfer",subtitle:"Models, Methods and Applications",isOpenForSubmission:!1,hash:"18bd3ce3b071e4f0cb9d4f58ac33c2fa",slug:"heat-transfer-models-methods-and-applications",bookSignature:"Konstantin Volkov",coverURL:"https://cdn.intechopen.com/books/images_new/6631.jpg",editedByType:"Edited by",editors:[{id:"118184",title:"Dr.",name:"Konstantin",middleName:null,surname:"Volkov",slug:"konstantin-volkov",fullName:"Konstantin Volkov"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5758",title:"Pyrolysis",subtitle:null,isOpenForSubmission:!1,hash:"536c8699f8fa7504a63a23de45158a24",slug:"pyrolysis",bookSignature:"Mohamed Samer",coverURL:"https://cdn.intechopen.com/books/images_new/5758.jpg",editedByType:"Edited by",editors:[{id:"175050",title:"Prof.",name:"Mohamed",middleName:null,surname:"Samer",slug:"mohamed-samer",fullName:"Mohamed Samer"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5452",title:"Distillation",subtitle:"Innovative Applications and Modeling",isOpenForSubmission:!1,hash:"ec5881c323f1825291a733ddb8356285",slug:"distillation-innovative-applications-and-modeling",bookSignature:"Marisa Fernandes Mendes",coverURL:"https://cdn.intechopen.com/books/images_new/5452.jpg",editedByType:"Edited by",editors:[{id:"35803",title:"Dr.",name:"Marisa",middleName:null,surname:"Mendes",slug:"marisa-mendes",fullName:"Marisa Mendes"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}},{type:"book",id:"5143",title:"Chemical Enhanced Oil Recovery (cEOR)",subtitle:"a Practical Overview",isOpenForSubmission:!1,hash:"a0b7842ba790370b5485de1694611376",slug:"chemical-enhanced-oil-recovery-ceor-a-practical-overview",bookSignature:"Laura Romero-Zeron",coverURL:"https://cdn.intechopen.com/books/images_new/5143.jpg",editedByType:"Edited by",editors:[{id:"109465",title:"Dr.",name:"Laura",middleName:null,surname:"Romero-Zerón",slug:"laura-romero-zeron",fullName:"Laura Romero-Zerón"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter",authoredCaption:"Edited by"}}],booksByTopicTotal:38,mostCitedChapters:[{id:"13254",doi:"10.5772/13474",title:"Insight Into Adsorption Thermodynamics",slug:"insight-into-adsorption-thermodynamics",totalDownloads:6549,totalCrossrefCites:58,totalDimensionsCites:154,book:{slug:"thermodynamics",title:"Thermodynamics",fullTitle:"Thermodynamics"},signatures:"Papita Saha and Shamik Chowdhury",authors:[{id:"13943",title:"Dr.",name:"Papita",middleName:null,surname:"Saha",slug:"papita-saha",fullName:"Papita Saha"},{id:"24184",title:"Mr.",name:"Shamik",middleName:null,surname:"Chowdhury",slug:"shamik-chowdhury",fullName:"Shamik Chowdhury"}]},{id:"23520",doi:"10.5772/20206",title:"Dissolution Trapping of Carbon Dioxide in Reservoir Formation Brine – A Carbon Storage Mechanism",slug:"dissolution-trapping-of-carbon-dioxide-in-reservoir-formation-brine-a-carbon-storage-mechanism",totalDownloads:5058,totalCrossrefCites:30,totalDimensionsCites:80,book:{slug:"mass-transfer-advanced-aspects",title:"Mass Transfer",fullTitle:"Mass Transfer - Advanced Aspects"},signatures:"Stefan Iglauer",authors:[{id:"37799",title:"Dr.",name:"Stefan",middleName:null,surname:"Iglauer",slug:"stefan-iglauer",fullName:"Stefan Iglauer"}]},{id:"13466",doi:"10.5772/13548",title:"Microwave Heating Applied to Pyrolysis",slug:"microwave-heating-applied-to-pyrolysis",totalDownloads:5118,totalCrossrefCites:18,totalDimensionsCites:76,book:{slug:"advances-in-induction-and-microwave-heating-of-mineral-and-organic-materials",title:"Advances in Induction and Microwave Heating of Mineral and Organic Materials",fullTitle:"Advances in Induction and Microwave Heating of Mineral and Organic Materials"},signatures:"Yolanda Fernandez, Ana Arenillas and J. Angel Menendez",authors:[{id:"14045",title:"Dr.",name:"J. Angel",middleName:null,surname:"Menéndez Díaz",slug:"j.-angel-menendez-diaz",fullName:"J. Angel Menéndez Díaz"},{id:"15134",title:"Dr.",name:"Ana",middleName:null,surname:"Arenillas",slug:"ana-arenillas",fullName:"Ana Arenillas"},{id:"15135",title:"Dr.",name:"Yolanda",middleName:null,surname:"Fernandez",slug:"yolanda-fernandez",fullName:"Yolanda Fernandez"}]}],mostDownloadedChaptersLast30Days:[{id:"56034",title:"Pyrolysis: A Sustainable Way to Generate Energy from Waste",slug:"pyrolysis-a-sustainable-way-to-generate-energy-from-waste",totalDownloads:5261,totalCrossrefCites:12,totalDimensionsCites:17,book:{slug:"pyrolysis",title:"Pyrolysis",fullTitle:"Pyrolysis"},signatures:"Chowdhury Zaira Zaman, Kaushik Pal, Wageeh A. Yehye, Suresh\nSagadevan, Syed Tawab Shah, Ganiyu Abimbola Adebisi, Emy\nMarliana, Rahman Faijur Rafique and Rafie Bin Johan",authors:[{id:"198251",title:"Dr.",name:"Zaira",middleName:null,surname:"Chowdhury",slug:"zaira-chowdhury",fullName:"Zaira Chowdhury"},{id:"208451",title:"Associate Prof.",name:"Kaushik",middleName:null,surname:"Pal",slug:"kaushik-pal",fullName:"Kaushik Pal"}]},{id:"44033",title:"Ion-Exchange Chromatography and Its Applications",slug:"ion-exchange-chromatography-and-its-applications",totalDownloads:27013,totalCrossrefCites:6,totalDimensionsCites:16,book:{slug:"column-chromatography",title:"Column Chromatography",fullTitle:"Column Chromatography"},signatures:"Özlem Bahadir Acikara",authors:[{id:"109364",title:"Dr.",name:"Özlem",middleName:null,surname:"Bahadır Acıkara",slug:"ozlem-bahadir-acikara",fullName:"Özlem Bahadır Acıkara"}]},{id:"59836",title:"Carbon Dioxide Conversion to Methanol: Opportunities and Fundamental Challenges",slug:"carbon-dioxide-conversion-to-methanol-opportunities-and-fundamental-challenges",totalDownloads:3896,totalCrossrefCites:2,totalDimensionsCites:5,book:{slug:"carbon-dioxide-chemistry-capture-and-oil-recovery",title:"Carbon Dioxide Chemistry, Capture and Oil Recovery",fullTitle:"Carbon Dioxide Chemistry, Capture and Oil Recovery"},signatures:"Sajeda A. Al-Saydeh and Syed Javaid Zaidi",authors:[{id:"193992",title:"Prof.",name:"Syed",middleName:null,surname:"Zaidi",slug:"syed-zaidi",fullName:"Syed Zaidi"},{id:"233125",title:"MSc.",name:"Sajeda",middleName:null,surname:"Alsaydeh",slug:"sajeda-alsaydeh",fullName:"Sajeda Alsaydeh"}]},{id:"57510",title:"Solvents for Carbon Dioxide Capture",slug:"solvents-for-carbon-dioxide-capture",totalDownloads:2173,totalCrossrefCites:4,totalDimensionsCites:10,book:{slug:"carbon-dioxide-chemistry-capture-and-oil-recovery",title:"Carbon Dioxide Chemistry, Capture and Oil Recovery",fullTitle:"Carbon Dioxide Chemistry, Capture and Oil Recovery"},signatures:"Fernando Vega, Mercedes Cano, Sara Camino, Luz M. Gallego\nFernández, Esmeralda Portillo and Benito Navarrete",authors:[{id:"10704",title:"Prof.",name:"Benito",middleName:null,surname:"Navarrete",slug:"benito-navarrete",fullName:"Benito Navarrete"},{id:"209759",title:"Dr.",name:"Fernando",middleName:null,surname:"Vega",slug:"fernando-vega",fullName:"Fernando Vega"},{id:"218843",title:"Dr.",name:"Mercedes",middleName:null,surname:"Cano",slug:"mercedes-cano",fullName:"Mercedes Cano"},{id:"218844",title:"Mrs.",name:"Sara",middleName:null,surname:"Camino",slug:"sara-camino",fullName:"Sara Camino"},{id:"218845",title:"Mrs.",name:"Luz. M.",middleName:null,surname:"Gallego Fernández",slug:"luz.-m.-gallego-fernandez",fullName:"Luz. M. Gallego Fernández"},{id:"218846",title:"Mrs.",name:"Esmeralda",middleName:null,surname:"Portillo",slug:"esmeralda-portillo",fullName:"Esmeralda Portillo"}]},{id:"52155",title:"EOR Processes, Opportunities and Technological Advancements",slug:"eor-processes-opportunities-and-technological-advancements",totalDownloads:4284,totalCrossrefCites:9,totalDimensionsCites:12,book:{slug:"chemical-enhanced-oil-recovery-ceor-a-practical-overview",title:"Chemical Enhanced Oil Recovery (cEOR)",fullTitle:"Chemical Enhanced Oil Recovery (cEOR) - a Practical Overview"},signatures:"Lezorgia Nekabari Nwidee, Stephen Theophilus, Ahmed Barifcani,\nMohammad Sarmadivaleh and Stefan Iglauer",authors:[{id:"37799",title:"Dr.",name:"Stefan",middleName:null,surname:"Iglauer",slug:"stefan-iglauer",fullName:"Stefan Iglauer"},{id:"179076",title:"Dr.",name:"Lezorgia",middleName:"Nekabari",surname:"Nwidee",slug:"lezorgia-nwidee",fullName:"Lezorgia Nwidee"},{id:"179077",title:"Prof.",name:"Ahmed",middleName:null,surname:"Barifcani",slug:"ahmed-barifcani",fullName:"Ahmed Barifcani"},{id:"179078",title:"Prof.",name:"Stephen",middleName:null,surname:"Theophilus",slug:"stephen-theophilus",fullName:"Stephen Theophilus"},{id:"189371",title:"Dr.",name:"Mohammad",middleName:null,surname:"Sarmadivaleh",slug:"mohammad-sarmadivaleh",fullName:"Mohammad Sarmadivaleh"}]},{id:"54078",title:"Distillation Techniques in the Fruit Spirits Production",slug:"distillation-techniques-in-the-fruit-spirits-production",totalDownloads:3686,totalCrossrefCites:6,totalDimensionsCites:12,book:{slug:"distillation-innovative-applications-and-modeling",title:"Distillation",fullTitle:"Distillation - Innovative Applications and Modeling"},signatures:"Nermina Spaho",authors:[{id:"189124",title:"Associate Prof.",name:"Nermina",middleName:null,surname:"Spaho",slug:"nermina-spaho",fullName:"Nermina Spaho"}]},{id:"60752",title:"Biomaterial from Oil Palm Waste: Properties, Characterization and Applications",slug:"biomaterial-from-oil-palm-waste-properties-characterization-and-applications",totalDownloads:1669,totalCrossrefCites:7,totalDimensionsCites:12,book:{slug:"palm-oil",title:"Palm Oil",fullTitle:"Palm Oil"},signatures:"Rudi Dungani, Pingkan Aditiawati, Sri Aprilia, Karnita Yuniarti, Tati\nKarliati, Ichsan Suwandhi and Ihak Sumardi",authors:[{id:"220081",title:"Dr.",name:"Pingkan",middleName:null,surname:"Aditiawati",slug:"pingkan-aditiawati",fullName:"Pingkan Aditiawati"},{id:"234728",title:"Dr.",name:"Rudi",middleName:null,surname:"Dungani",slug:"rudi-dungani",fullName:"Rudi Dungani"},{id:"249537",title:"Dr.",name:"Sri",middleName:null,surname:"Aprilia",slug:"sri-aprilia",fullName:"Sri Aprilia"},{id:"249539",title:"Dr.",name:"Karnita",middleName:null,surname:"Yuniarti",slug:"karnita-yuniarti",fullName:"Karnita Yuniarti"},{id:"249541",title:"Dr.",name:"Tati",middleName:null,surname:"Karliati",slug:"tati-karliati",fullName:"Tati Karliati"},{id:"249542",title:"Dr.",name:"Ichsan",middleName:null,surname:"Suwandi",slug:"ichsan-suwandi",fullName:"Ichsan Suwandi"},{id:"249543",title:"Dr.",name:"Ihak",middleName:null,surname:"Sumardi",slug:"ihak-sumardi",fullName:"Ihak Sumardi"},{id:"256251",title:"Dr.",name:"Sri",middleName:null,surname:"Hartati",slug:"sri-hartati",fullName:"Sri Hartati"}]},{id:"51915",title:"Microbial Enhanced Oil Recovery",slug:"microbial-enhanced-oil-recovery-2016-10-14",totalDownloads:3903,totalCrossrefCites:3,totalDimensionsCites:8,book:{slug:"chemical-enhanced-oil-recovery-ceor-a-practical-overview",title:"Chemical Enhanced Oil Recovery (cEOR)",fullTitle:"Chemical Enhanced Oil Recovery (cEOR) - a Practical Overview"},signatures:"Aliya Yernazarova, Gulzhan Kayirmanova, Almagul Baubekova and\nAzhar Zhubanova",authors:[{id:"178534",title:"Ph.D.",name:"Aliya",middleName:null,surname:"Yernazarova",slug:"aliya-yernazarova",fullName:"Aliya Yernazarova"},{id:"179203",title:"Dr.",name:"Gulzhan",middleName:null,surname:"Kaiyrmanova",slug:"gulzhan-kaiyrmanova",fullName:"Gulzhan Kaiyrmanova"},{id:"191673",title:"Dr.",name:"Almagul",middleName:null,surname:"Baubekova",slug:"almagul-baubekova",fullName:"Almagul Baubekova"},{id:"194422",title:"Dr.",name:"Azhar",middleName:null,surname:"Zhubanova",slug:"azhar-zhubanova",fullName:"Azhar Zhubanova"}]},{id:"58728",title:"Techniques for the Fabrication of Super-Hydrophobic Surfaces and Their Heat Transfer Applications",slug:"techniques-for-the-fabrication-of-super-hydrophobic-surfaces-and-their-heat-transfer-applications",totalDownloads:1622,totalCrossrefCites:3,totalDimensionsCites:4,book:{slug:"heat-transfer-models-methods-and-applications",title:"Heat Transfer",fullTitle:"Heat Transfer - Models, Methods and Applications"},signatures:"Hafiz Muhammad Ali, Muhammad Arslan Qasim, Sullahuddin Malik\nand Ghulam Murtaza",authors:[{id:"187624",title:"Dr.",name:"Hafiz Muhammad",middleName:null,surname:"Ali",slug:"hafiz-muhammad-ali",fullName:"Hafiz Muhammad Ali"},{id:"233669",title:"MSc.",name:"Arslan",middleName:null,surname:"Qasim",slug:"arslan-qasim",fullName:"Arslan Qasim"},{id:"236423",title:"MSc.",name:"Sullahuddin",middleName:null,surname:"Malik",slug:"sullahuddin-malik",fullName:"Sullahuddin Malik"},{id:"236424",title:"MSc.",name:"Ghulam",middleName:null,surname:"Murtaza",slug:"ghulam-murtaza",fullName:"Ghulam Murtaza"}]},{id:"38711",title:"Hydrogen Storage for Energy Application",slug:"hydrogen-storage-for-energy-application",totalDownloads:11233,totalCrossrefCites:11,totalDimensionsCites:20,book:{slug:"hydrogen-storage",title:"Hydrogen Storage",fullTitle:"Hydrogen Storage"},signatures:"Rahul Krishna, Elby Titus, Maryam Salimian, Olena Okhay, Sivakumar Rajendran, Ananth Rajkumar, J. M. G. Sousa, A. L. C. Ferreira, João Campos Gil and Jose Gracio",authors:[{id:"25491",title:"Dr.",name:"Elby",middleName:null,surname:"Titus",slug:"elby-titus",fullName:"Elby Titus"}]}],onlineFirstChaptersFilter:{topicSlug:"engineering-chemical-engineering",limit:3,offset:0},onlineFirstChaptersCollection:[],onlineFirstChaptersTotal:0},preDownload:{success:null,errors:{}},aboutIntechopen:{},privacyPolicy:{},peerReviewing:{},howOpenAccessPublishingWithIntechopenWorks:{},sponsorshipBooks:{sponsorshipBooks:[{type:"book",id:"10176",title:"Microgrids and Local Energy Systems",subtitle:null,isOpenForSubmission:!0,hash:"c32b4a5351a88f263074b0d0ca813a9c",slug:null,bookSignature:"Prof. Nick Jenkins",coverURL:"https://cdn.intechopen.com/books/images_new/10176.jpg",editedByType:null,editors:[{id:"55219",title:"Prof.",name:"Nick",middleName:null,surname:"Jenkins",slug:"nick-jenkins",fullName:"Nick Jenkins"}],equalEditorOne:null,equalEditorTwo:null,equalEditorThree:null,productType:{id:"1",chapterContentType:"chapter"}}],offset:8,limit:8,total:1},route:{name:"profile.detail",path:"/profiles/244075/alberto-gonzalez-martinez",hash:"",query:{},params:{id:"244075",slug:"alberto-gonzalez-martinez"},fullPath:"/profiles/244075/alberto-gonzalez-martinez",meta:{},from:{name:null,path:"/",hash:"",query:{},params:{},fullPath:"/",meta:{}}}},function(){var e;(e=document.currentScript||document.scripts[document.scripts.length-1]).parentNode.removeChild(e)}()