Open access peer-reviewed chapter

A Novel Application of Oceanic Biopolymers — Strategic Regulation of Polymer Characteristics for Membrane Technology in Separation Engineering

Written By

Keita Kashima, Ryuhei Nomoto and Masanao Imai

Submitted: 16 May 2015 Reviewed: 16 November 2015 Published: 09 March 2016

DOI: 10.5772/61998

From the Edited Volume

Recent Advances in Biopolymers

Edited by Farzana Khan Perveen

Chapter metrics overview

1,784 Chapter Downloads

View Full Metrics

Abstract

Membranes prepared from oceanic biopolymers have a high potential in membrane separation processes and water purification. It is anticipated to result in more biocompatible and lower-cost materials compared with artificial polymers. This chapter describes the excellent performance of oceanic biopolymer membranes in separation engineering and the regulation factors controlling membrane properties. In particular, chitosan and alginate were picked up as intelligent membrane materials to provide the promised molecular size recognition and other membrane properties. Future prospective strategies for a simple methodology for preparing stable membranes from oceanic biopolymers and the development of selective separation processing were reviewed.

Keywords

  • Membrane
  • oceanic biopolymer
  • chitosan
  • alginate
  • mechanical strength
  • mass transfer characteristics

1. Introduction

1.1. Overview of oceanic biopolymers in membrane separation technology

Membrane separation technology has been applied in various fields, such as the chemical industry, food production, pharmaceutical products, environmental sciences, and water purification, because it can be operated without heating and residual toxicity. Its energy cost was lower than conventional thermal separation technologies [14]. It can be employed for broad components by selecting optimum membranes.

Development of oceanic biopolymer membranes such as chitosan and alginate has exponentially increased due to increases in the demand for biocompatibility, environment adaptability, renewability, and selective separation ability [56]. In the field of membrane science, most membranes have been made from petroleum-based polymers used as raw materials for the membrane body. Petroleum-based synthetic polymers such as polyethylene, polyamide, polyimide, and polysulfonate have been used as the main materials of the membrane body for a long time. The practical use of biopolymer membranes was less than synthetic polymer membranes, because controlling the physical and chemical properties of a biopolymer produced from natural bioresources was difficult in practical membrane applications. Cellulose-based membranes have been extensively used in practical applications since the development of the anisotropic cellulose acetate membrane in 1963 by Loeb and Sourirajan [7]. Applications of biopolymer materials have increased recently for membrane sciences [8]. Recent studies of biopolymer membranes are summarized in Table 1 referred to previous literatures [9-22]. In the past five years, oceanic biopolymers have attracted attention for their chemical functional ability. Investigations of oceanic biopolymer membranes, especially chitosan and alginate, for various applications have drastically increased.

Table 1.

Recent investigations of biopolymer membrane and applications.

Kashima, Nomoto and Imai 2015.


The common aim of membrane separation technology is to separate a target component from a mixture with the aid of permeation through the membrane, while rejecting other components. The key characteristics for practical use are as follows: mechanical strength, permeation flux, diffusivity of molecule, and micro-/nanostructure. This chapter describes the dominant factors in controlling important properties for practical membrane separation applications for oceanic polymer membrane, especially those of chitosan and alginate.

Advertisement

2. Chitosan membrane

Chitosan is a well-known sustainable and biocompatible oceanic biomaterial. It has been attracted in creating new polymer materials for broad application due to its nontoxicity, biocompatibility, and biodegradability [5]. Chitosan is refined by removing an acetyl group from chitin, which is mainly produced in oceanic bioresources such as the shells of crabs and shrimps. Chitin is the second most abundant natural polymer in nature, after cellulose [23]. Chitosan is generally discarded as industrial waste around the world [24]. It is strongly expected to be useful as a biocompatible and reactive material for making functional gel membranes. Recent studies of various chitosan membranes are summarized in Table 2 and Table 3 referred to previous literatures [5-6, 12, 15-19, 24-46].

2.1. Chemical composition and membrane formation

Chitosan is a heteropolymer obtained by alkaline deacetylation of chitin at the C-2 position as shown in Figure 1 (a) and (b). Chitosan is generally defined by a deacetylation degree (DD [%]) of 60–100%. The deacetylation degree is estimated as follows:

DD=nGSnGS+nAGS×100E1

Here, nGS (nAGS) is the molar number of glucosamine residues (acetylglucosamine residues) in the molecular chain. Chitosan has great potential for chemical modification because its molecular chain has a rich amino group and a hydroxyl group in the glucosamine residues [29].

Figure 1.

Chemical structure of chitosan showing β-1,4-D-glycoside linkage. (a) Chitin molecular chain consisting of poly-β-1,4-D-N-acetylglucosamine residues, (b) chitosan molecular chain consisting of poly-β-1,4-D-glucosamine residues.

The beneficial effects of chitosan are as a dietary fiber, such as its inhibition of fat digestibility [47] and its reduction of cholesterols [48]. The biodegradability and biocompatibility of chitosan are also suitable for biomedical applications [49].

Table 2.

Recent investigations of chitosan membrane (2012–2014).

Kashima, Nomoto and Imai 2015.


Chitosan is dissolved in an acid aqueous solution, such as acetic acid. To form a water-insoluble chitosan membrane, the acetic acid has to be neutralized by basic components. The authors have reported preparation of chitosan membrane using casting methods [16]. For example, 4 g of chitosan was dissolved in 198 mL of 1.7 mol・L–1 acetic acid aqueous solution. The solution was mixed magnetically for 12 h at room temperature to obtain a mature solution. Some insoluble matter was removed by vacuum filtration using a filter paper (Grade No. 1, ADVANTEC, Japan). The concentration of the chitosan casting solution was 0.02 g-chitosan・mL-chitosan casting solution–1. Ten grams of the casting solution was dispensed in a glass Petri dish (inner diameter 7.75 cm) and dried in a thermostatic chamber at 333 K for 24 h. A dried chitosan membrane formed on the glass Petri dish. A 20 mL of sodium hydroxide (NaOH) aqueous solution was directly introduced onto the dried chitosan membrane. The chitosan membrane was continuously immersed for 3 h in NaOH solution for neutralization. The concentration of the supplied NaOH ranged from 0.1 to 5 mol・L–1. In this case, the stoichiometric equivalent concentration of NaOH was estimated to be 0.83 mol・L–1. After neutralization, the swollen membrane was easily separated from the glass Petri dish and was washed fully with pure water to remove excess NaOH.

Table 3.

Most recent investigations of chitosan membrane (2015).

Kashima, Nomoto and Imai 2015.


2.2. Dominant role of the acid–base neutralization in chitosan membrane characteristics

The authors previously reported the dominant role of the acid–base neutralization process in forming chitosan membranes for controlling some membrane properties [16].

2.2.1. Mechanical strength

The mechanical strength, maximum tensile stress (Figure 2a), and maximum strain (Figure 2b) at membrane rupture presented bell-shaped curves with peaks when the NaOH concentration increased. For an 81% DD chitosan membrane, the maximum stress and the maximum strain reached maximum values of 8.6 MPa and 80.5%, respectively, in a membrane prepared with 1 mol・L–1 NaOH. This concentration was almost the same as the stoichiometric equivalent concentration (0.83 mol・L–1). In contrast, in a 98% DD chitosan membrane, the maximum stress and the maximum strain increase to 17.9 MPa and 134% when the membrane was prepared with 2 mol・L–1 NaOH.

Figure 2.

Effect of NaOH concentration in neutralization on the maximum stress (a) and maximum strain (b) at membrane rupture in reference [16]. The dashed line represents the stoichiometric neutralization concentration of NaOH (0.83 mol・L–1).

2.2.2. Water permeation flux

Figure 3 demonstrates that the water permeation flux and the volumetric void fraction of the swollen membrane were almost linearly correlated. The NaOH concentration in the neutralization process enhanced both the water permeation flux and the void fraction in the membrane. Neutralization using a high NaOH concentration weakens hydrogen bonding between chitosan polymer chains. The void fraction in the swollen membrane can assumed to be the volume of a water permeation channel occupying the membrane. This result suggests that the membrane structure involving water permeation was dominantly regulated by the NaOH concentration during neutralization.

Figure 3.

Correlation between the water permeation flux and the void fraction of 81% deacetylation degree chitosan membrane in reference [16]. The concentrations of NaOH used in the neutralization process are indicated at adjacent to keys, respectively.

2.2.3. Mass transfer characteristics

The effective diffusion coefficient of the model components was evaluated based on the mass transfer flux. The membrane was sandwiched between twin mass transfer cells. The feed solution contained the model components (urea 60 Da, Methyl Orange 327 Da, Rose Bengal 1017 Da, and Sirius Red 1373 Da) at the desired concentrations, and the stripping solution was deionized water. The overall mass transfer coefficient KOL was evaluated from the mass transfer flux according to Eq. (2).

ln(12CsCfi)=2AKOLVtE2

Here, Cs and Cfi are the concentrations of the stripping and initial feed solutions, A is the mass transfer area of the membrane, V is the volume of aqueous phase in each transfer cell, and t is the operation time.

The overall mass transfer coefficient KOL included the film mass transfer resistances (kL1–1 and kL2–1) and the membrane mass transfer coefficient (km) as seen in Eq. (3).

KOL1=kL11+km1+kL21E3

The aqueous phases in the mass transfer cells were sufficiently stirred to attain a fully developed turbulent condition (Re > 104). The film mass transfer resistances (kL1–1 andkL2–1) within the overall mass transfer resistance (KOL–1) were ignored under fully turbulent conditions. This directly indicated the membrane mass transfer coefficient (km). The effective diffusion coefficient was evaluated from km using Eq. (4):

km=DeffE4

The initial membrane thickness in the swollen state () was measured with a micrometer (Mitutoyo Corporation, Kanagawa, Japan).

Figure 4 depicts the change in the effective diffusion coefficient in the chitosan membrane with the molecular weight of the tested components for 81% DD. The effective diffusion coefficient of a chitosan membrane prepared from NaOH of 1mol・L–1 changed dramatically at a molecular size corresponding to Rose Bengal (1017 Da). This result suggested that the size distribution of the mass transfer channel in the membrane was monodisperse and similar to the molecular size of Rose Bengal.

Figure 4.

Change of effective diffusion coefficient (Deff) versus molecular weight of tested components (81% deacetylation) [16].

The effective diffusion coefficient of a membrane prepared from 5 mol・L–1 NaOH greatly increased relative to a membrane prepared from 1 mol・L–1. The molecular diffusion channel formed by the polymer networks became enlarged due to the higher NaOH concentration employed.

The dominant role of the acid–base neutralization process in chitosan membranes was revealed to control membrane properties involving mechanical strength, the water permeation flux, and the effective diffusion coefficient.

2.2.4. Morphology of chitosan membrane

Figure 5 presents scanning probe microscope (SPM) photographs of chitosan membrane surfaces. The chitosan membrane made from 1 mol・L–1 NaOH had a very smooth surface. In contrast, the membrane made from 5 mol・L–1 NaOH had a somewhat rough surface.

Figure 5.

Scanning probe microscope photographs of chitosan membrane surface. (a) 1 mol L–1 NaOH, (b) 5 mol L–1 NaOH [16].

2.3. Other regulation factors

2.3.1. Deacetylation degree

The deacetylation degree (DD) of a chitosan membrane can be stoichiometrically controlled by an acetic anhydride additive. Effects of the deacetylation degree on membrane properties, such as water permeation flux, have been found [50]. The water permeation flux of a membrane prepared from 99.2% DD chitosan was remarkably enhanced about 100-fold compared with a 76.5% DD chitosan membrane. The water permeation flux increased exponentially with increasing deacetylation degree from 81.8% to 92.2% [51].

Increasing the deacetylation degree enhances the surface hydrophilicity of the membrane surface because the acetamido groups on the chitosan membrane are converted into amino groups. This advances the effective formation of hydrogen bonds between the amino and hydroxyl groups and between the amino groups in the chitosan molecules, thus resulting in a dense molecular chain in the membrane [18].

2.3.2. Molecular weights of chitosan

Chitosan membranes prepared by Uragami and coworkers from different molecular weights (13–201 kDa) were tested during pervaporation dehydration of an ethanol aqueous solution. The permeation flux decreased with increasing molecular weight from 13 kDa to 90 kDa, then increased from 90 kDa to 201 kDa. In contrast, the water permeation selectivity from the ethanol aqueous solution increased remarkably with increasing molecular weight up to 90 kDa. Over 90 kDa, the selectivity decreased. These results were understood to indicate that the 90 kDa molecular weight effectively formed entanglements and thus produced the strongest hydrogen bonds between the molecular chains of chitosan [18], although the mechanical strength increased with increasing average molecular weight of chitosan [52].

2.3.3. Addition of a cross-linker

Basically, chitosan can be formed into an insoluble membrane by acid–base neutralization in the casting solution without using a cross-linker. However, the addition of a cross-linker to improve membrane characteristics was carefully investigated.

The most prominent effect of an additive cross-linker is improved mechanical strength. Figure 6 depicts the change of mechanical strength of chitosan membrane (maximum stress vs. maximum strain at membrane rupture) with increasing amount of cross-linker. In a common trend, increasing the amount of cross-linker forms a rigid membrane. The addition of genipin as a cross-linker increased the maximum stress and reduced the maximum strain at membrane rupture [39]. Increasing added amounts of glutaraldehyde, methanol with ethylene glycol diglycidyl ether, and gallic acid also increased the mechanical strength. However, excess addition of cross-linker formed rigid and fragile structures on the chitosan membrane [2526, 53].

Figure 6.

Change of mechanical strength of chitosan membranes with increasing amount of cross-linker. ●: chitosan membrane cross-linked with genipin [54]. ■: chitosan membrane cross-linked with methanol and ethylene glycol diglycidyl ether [53]. ▲: chitosan membrane cross-linked with glutaraldehyde [25]. ◆: chitosan membrane cross-linked with gallic acid [26], ▼: chitosan cross-linked with tripolyphosphate [55]. Arrows indicate increasing additive amount of each cross-linker.

Other researchers have reported that cross-linking with sodium tripolyphosphate enhanced the mechanical strength of chitosan membrane [17]. From another viewpoint, Shenvi and coworkers determined the effect of the pH value of the cross-linking solution on the membrane properties. A chitosan membrane cross-linked by tripolyphosphate solution at pH 5 realized a higher rejection rate of NaCl and MgSO4 than a membrane cross-linked at pH 9 [28].

The enhancement of pervaporative dehydration ability of water–alcohol mixtures by adding cross-linker has been frequently reported [56]. A chitosan membrane cross-linked with toluene-2,4-diisocyanate exhibited high pervaporative dehydration ability with an isopropanol aqueous solution in which the selectivity of water α was performed as 472 [57]. The selectivity of water α was calculated using the following equation:

α=y(1x)x(1y)E5

Here, y is the permeate weight fraction of water and x is the feed weight fraction of water.

2.3.4. Hybrid approaches with other materials

Some hybrid approaches using chitosan and other materials have been proposed to overcome problems in practical use [35]. To make a porous structure on a chitosan membrane, SiO2, a porogen agent, was mixed with chitosan cast solution and removed from the membrane. The average pore size reached a maximum of 8.5 μm when the mixing ratio of chitosan and SiO2 was 1:2 [19].

Chitosan membranes are frequently combined with nanomaterial to form a composite medium. A chitosan membrane composited with a multi-walled carbon nanotube was modified by adding perfluorooctanesulfonyl fluoride (PFOSF). The added PFOSF enhanced antibacterial activity due to its remarkable hydrophobicity. The mechanical strength increased with increasing multi-walled carbon nanotubes [44]. Chitosan composited with ZnO nanoparticles was also investigated for antibacterial activity [46]. Chitosan membrane has a good potential as a composited nanomaterial medium for biologically based nanotechnology.

2.3.5. Chemical modification of the chitosan molecular chain

Chitosan has great potential for chemical modification. Functionalized chitosan is often used as the main membrane body, coating agent, or additive agent for functionalization of surface modifications. Graphene oxide functionalizing a chitosan membrane as a surface modification agent on a commercial polyamide membrane has been investigated. The water flux and NaCl rejection of the chitosan membrane were increased by the modification, due to the formation of a dense, thin layer of graphene-oxide-functionalized chitosan, which is better than natural chitosan membrane [40]. Kumar and coworkers prepared various chitosan membranes: a natural chitosan blended with polysulfone membrane, an N-succinylchitosan blended with polysulfone membrane, and an N-propylphosphonyl chitosan blended with polysulfone membrane. These membranes were applied to a heavy metal purification process. N-succinylchitosan blended with polysulfone membrane sufficiently purified Cu, Ni, and Cd [32].

Advertisement

3. Alginate membrane

Alginate is abundantly and sustainably produced by marine biological resources, especially brown seaweed. It has been widely applied in the food industry [58] and as a thickener [59], a suspending agent [60], an emulsion stabilizer [61], a gelling agent [62], and a film-forming agent [63]. In addition, alginate was continuously developed as useful materials for biomedical applications, especially for controlled delivery of drugs and other biologically active compounds and for the encapsulation of cells [64]. In recent pioneering works, alginate has developed as membrane material with excellent molecular selectivity for water-soluble components [65]. Recent studies of various alginate membranes are listed in Table 4 and Table 5 referred to previous literatures [10-11, 15, 22, 66-95].

3.1. Chemical composition and membrane formation of alginate

The molecular chain of alginate is constructed of a block copolymer of β-D-mannuronate (Figure 7a) and α-L-guluronate (Figure 7b) [96]. These two uronates construct a polymeric block in an alginate polymer chain with the following three types of block: homopolymeric blocks of α-L-guluronate (GG blocks), blocks with an alternating sequence in varying proportions of guluronate and mannuronate (MG blocks), and homopolymeric blocks of β-D-mannuronate (MM blocks) [97]. GG blocks chelate alkaline earth-metal ions because of the spatial arrangement of the pyranose ring and the hydroxyl oxygen atoms, and thus create a much stronger interaction than MM blocks and MG blocks [9899].

Figure 7.

Residues of alginate molecular chain. (a) β-D-mannuronate. (b) α-L-guluronate. (c) Chelation of homopolymeric blocks of α-L-guluronate junction with calcium ions. Alginate was cross-linked by divalent cations according to the “Egg-box” model.

Table 4.

Recent investigations of alginate membrane (2004–2013).

Kashima, Nomoto and Imai 2015.


Table 5.

Most recent investigations of alginate membrane (2014–2015).

Kashima, Nomoto and Imai 2015


Sodium alginate easily forms a cross-link with the presence of divalent cations such as Ca2+, resulting in a highly compacted and dense gel network. GG blocks are constructed mainly of a cross-linked zone with Ca2+. This is called an “Egg-box junction” (Figure 7c), where the ions were assimilated to “Eggs” [100].

Sodium alginate forms a cross-link in the presence of divalent cations such as Ca2+, resulting in a highly compacted gel network. Homopolymeric blocks of α-L-guluronate are constructed mainly of a cross-linked zone with divalent cations. This section describes the impact of this kind of divalent cations and the mass fraction of homopolymeric blocks of α-L-guluronate in an alginate polymer chain (FGG).

The authors previously reported the preparation of alginate membrane described below [1011]. A 20 mL sodium alginate aqueous solution (10 g・L–1) was placed in a Petri dish. The solution was gradually dried at a mild temperature in a desiccator (298 K) or an electrical dryer (303 K) for 24 h to prevent heat degradation. A dried, thin film of sodium alginate was obtained on the Petri dish.

An electrolyte aqueous solution (CaCl2, SrCl2, and BaCl2) was directly introduced onto the dried, thin sodium alginate film as a source of divalent cation for cross-linking. The concentration range of the electrolyte aqueous solutions was 0.1–1.0 mol・L–1. A stable alginate membrane was quickly formed in the Petri dish at room temperature. After 20 min, the prepared swollen membrane was spontaneously separated from the surface of the Petri dish. The membrane remained in the electrolyte aqueous solution for further 20 min. The membrane was totally immersed in the electrolyte aqueous solution for 40 min. The prepared membrane was repeatedly washed with pure water to remove excess electrolyte, and then stored in pure water.

3.2. Effect of homopolymeric block of α-L-guluronate (FGG)

The authors previously reported that membrane properties are evidently controlled by the mass fraction (FGG) [11, 65, 101]. At first, the mass of GG blocks in the actual alginate polymer chain was determined by acid hydrolysis combined with Bitter–Muir’s carbazole sulfuric acid method [102]. The actual alginate was separated into three fractions (GG block, MM block, and MG block) by the acid-hydrolysis method. Acid-hydrolysis protocols were employed according to a previously published method [11, 103]. Their obtained fractions were then determined by Bitter–Muir’s carbazole sulfuric acid method using an optical density of 530 nm (UV-1200, Shimadzu, Kyoto, Japan). The calibration curve for mannuronic acid lactone was obtained and used as the standard component of uronic acid. These methods produced good intensity and accuracy of coloration [104].

The mass of the GG block (WGG) was obtained from a fractional solution of the GG block by acid hydrolysis. The masses of the MM block (WMM) and MG block (WMG) were determined in the same way. The mass fraction of the homopolymeric blocks of α-L-guluronate (FGG) was then calculated using the following formula:

FGG=WGGWGG+WMM+WMGE6

FGG was therefore shown to be a key factor in regulating membrane properties. In this study, two sodium alginates were examined, FGG 0.18 and FGG 0.56. Calcium alginate membrane prepared from five types of sodium alginate (FGG 0.18, 026, 0.35, 0.45, and 0.56) were regulated by mixing with two types of sodium alginate (FGG 0.18 and 0.56).

3.2.1. Mechanical strength

The effect of FGG on mechanical strength is depicted in Figure 8. The mechanical strength was determined based on the membrane deformation. The maximum stress was defined at the rupture of the membrane. This value increased with increasing FGG. In contrast, the maximum strain decreased with increasing FGG. The mechanical properties of the calcium alginate membrane changed from elastic to plastic transfer, depending on FGG.

Figure 8.

Effect of FGG on mechanical strength of calcium alginate membrane [11].

3.2.2. Mass transfer characteristics

An alginate membrane performs superior molecular size recognition on low-molecular-weight components from 60 Da to 600Da [10]. Figure 9 demonstrates that the effective diffusion coefficient in the membrane (Deff) of saccharides (glucose, G, 180Da; maltose, M, 324 Da; raffinose, R, 504 Da) can be efficiently changed by regulating FGG. The effective diffusion coefficient in the membrane prepared from FGG 0.56 alginate was proportional to the –4.6th power of the molecular volume. The diffusion coefficient in bulk aqueous phase (D0) was inversely proportional to the 0.6th power of the molecular volume [105]. In contrast, the effective diffusion coefficient in the membrane prepared from FGG 0.18 alginate was proportional to the –2.9th power of the molecular volume. The higher FGG membrane exhibited more sensitive molecular size recognition. “Egg-box junction” zones constructed from calcium ions and homopolymeric blocks of α-L-guluronate dominantly regulated the mass transfer mechanism of the alginate membrane.

Figure 9.

The effective diffusion coefficient changed remarkably in our experimental range from 180 Da to 504 Da. The symbol ◆ indicates the diffusion coefficient in bulk aqueous solution. Temperature: 303 K. Agitation rate: 14.2 s–1 [65].

The effect of FGG on the mass transfer characteristics was evaluated using a permeation test with urea aqueous solution as a typical molecule model. The effective diffusion coefficient (Deff) of urea in the membrane decreased with increasing FGG. Figure 10 illustrates the correlation of the volumetric void fraction of the swollen membrane with the ratio between the effective diffusion coefficient of urea in the membrane and the diffusion coefficient in bulk aqueous phase (D0). Both the effective diffusion coefficient and the volumetric water fraction were restrained by increasing FGG. The strong dependency of the effective diffusion coefficient of urea on the void fraction contributes to good understanding of the formation of a mass transfer channels in the alginate membrane. These channels are speculated as being monodisperse in a similar size with urea molecule. The mass transfer channel was governed by the mass fraction of homopolymeric blocks of α-L-guluronate (FGG).

Figure 10.

Correlation of the volumetric void fraction of the swollen membrane with the effective diffusion coefficient of urea [11].

3.2.3. Morphology of the alginate membrane

Figure 11 presents SPM photographs of the calcium alginate membrane surface. The distribution of membrane asperity clearly decays with increasing FGG. Especially in higher FGG conditions, many of the GG blocks formed a higher population density of Egg-box junction chelating with Ca2+, and the atomic force of the polymer networks was uniform.

Figure 11.

Scanning probe microscope photographs of calcium alginate membrane surface. (a) FGG = 0.18, (b) FGG = 0.56.

3.3. Effect of cross-linking divalent cations

The authors prepared a stable alginate membrane cross-linked with CaCl2, SrCl2, and BaCl2. These membranes are sufficiently stable in aqueous phase to apply for practical use.

3.3.1. Water permeability

The water permeation coefficient was evaluated based on the pure water permeation flux as presented in Figure 12. It was decreased logarithmically with increasing concentration of cross-linker. This suggests that the number of permeation channels and/or the size of the permeation channels decreased with increasing concentration of cross-linking ions. The effect of cross-linker concentration on water permeability appeared strongly in the BaCl2 used, suggesting that Ba2+ structures have a much stronger interaction in α-L-guluronate block. Binding of divalent cation to the three kind of copolymer blocks have been investigated [106107]. The following orders of binding strength indicated by sign of equality were reported:

GG block: Ba > Sr> Ca >> MgMM block: Ba > SrCaMgMG block: BaSrCaMgBB1

Hence, the alginate membrane cross-linked with BaCl2 constructed a dense polymer network due to strong bonding between alginate molecular chain and Ba2+.

Figure 12.

Effect of concentration of cross-linking electrolyte solution on water permeation coefficient.

3.3.2. Volumetric water fraction

The volumetric water content of a swollen membrane can be assumed to an indicator of the void fraction of the membrane structure [108]. Figure 13 illustrates the effect of the concentration of electrolyte solution on the void fraction of the membrane. The void fraction decreased with increasing concentration of the cross-linking electrolyte solution. An alginate membrane cross-linked with BaCl2 was highly densified by the provided Ba2+.

Figure 13.

Effect of concentration of cross-linking electrolyte solution on void fraction of swollen alginate membrane.

3.4. Other regulation factors for controlling membrane properties

3.4.1. Addition of cross-linker other than metal ions

Conventional cross-linkers forming a polymer membrane were also examined to realize the alginate membrane. Glutaraldehyde is most commonly employed as a cross-linker to form sodium alginate membranes [8384]. These membranes cross-linked with glutaraldehyde were developed for use in organic dehydration by pervaporation [66, 79, 82]. A sodium alginate membrane cross-linked with phosphoric acid was prepared for pervaporative dehydration of ethanol aqueous solution [67]. This resulted in 3.5 × 10–2 kg・m–2・h–1 of permeation flux and 2182 of selectivity as defined by Eq. (4). A sodium alginate membrane cross-linked by sodium tartrate was characterized by CO2 capture from CO2/N2 [78].

3.4.2. Hybrids with other polymers or materials

Many efforts have been made to enhance the performance of the alginate membrane by blending it with different hydrophilic polymers. An alginate-blended DNA membrane cross-linked with Mg2+ or Ca2+ was investigated with regard to the permeation flux of ethanol aqueous solution for pervaporation [95]. The permeation flux and selectivity of a calcium alginate membrane with DNA in pervaporative dehydration for an ethanol aqueous solution were measured as 1.2×10–2 kg・m–2・h–1 and 5500, respectively. In contrast, a magnesium alginate membrane with DNA exhibited a permeation flux and selectivity of 1.2×10–2 kg・m–2・h–1 and 6500.

Hybrid membranes of sodium alginate and dextrin cross-linked with glutaraldehyde had a permeation flux of 9.65 × 10–2 kg・m–2・h–1 permeation flux and a selectivity of 8991 in pervaporative dehydration for an isopropanol aqueous solution [68].

Alginate membranes are frequently combined with nanomaterials to form a composite medium. A calcium alginate membrane containing multi-walled carbon nanotubes was prepared as a new nanofiltration membrane. It had high mechanical strength, antifouling ability, and high rejection of small organic molecules (Congo Red, 697Da) [92].

Advertisement

4. Conclusion

Strategic regulation of an oceanic biopolymer membrane to control its characteristics in membrane separation technology was demonstrated. An oceanic biopolymer chitosan membrane can be easily prepared by casting chitosan in dilute aqueous organic acids and neutralizing it with an alkaline aqueous solution. The dominant role of neutralization for chitosan membrane involves the mechanical strength, the permeation flux, and the mass transfer characteristics. Other regulating factors, such as the deacetylation degree, the average molecular weight, and the addition of a cross-linker were presented.

A calcium alginate membrane performs superior molecular size recognition on low-molecular-weight components from 60 Da to 600 Da due to a dense polymer network consisting of homopolymeric blocks of α-L-guluronate and calcium ions. The kind of cross-linking ion used is also able to control the membrane properties. Barium ion performed a stronger cross-linker in the alginate membrane rather than Ca2+ and Sr2+, and a highly complex structure was formed. The mass fraction of homopolymeric blocks of α-L-guluronate and cross-linking metal ions were impact factors in regulating the mass transfer characteristics, water permeability, and mechanical strength.

These oceanic polymers are biodegradable, biocompatible, environmentally friendly, stable, and easily available from renewable agricultural resources. In the future, oceanic biopolymer membranes should be developed as an alternative to artificial polymer membranes.

Advertisement

Nomenclature

A Area of membrane surface [m2]

Cfi Initial concentration in the feed solution [mol・L–1]

Cs Concentration in the stripping solution [mol・L–1]

D0 Diffusion coefficient in a bulk aqueous phase estimated from Wilke–Chang’s empirical formula [m2・s–1]

DD Deacetylation degree [%]

Deff Effective diffusion coefficient [m2・s–1]

FGG Mass fraction of GG block inalginate determined by Eq. (5) [–]

KOL Overall mass transfer coefficient [m・s–1]

KOL–1 Overall mass transfer resistance [(m・s–1)–1]

km Membrane mass transfer coefficient [m・s–1]

kL1 Film mass transfer coefficient in the feed phase [m・s–1]

kL2 Film mass transfer coefficient in the stripping phase [m・s–1]

Membrane thickness in the initial state [m]

nAGS Molar number of acetylglucosamine residues in polymer chain of chitin or chitosan [mol]

nGS Molar number of glucosamine residues in polymer chain of chitin or chitosan [mol]

Re Reynolds number [–]

t Time [s]

V Volume of aqueous solution in the transfer cell [m3]

WGG Mass of GG block in sodium alginate [kg]

WMG Mass of MG block in sodium alginate [kg]

WMM Mass of MM block in sodium alginate [kg]

x Feed weight fraction of water in pervaporation [–]

y Permeate weight fraction of water in pervaporation [–]

α separation factor on pervaporative dehydration defined by Eq. (4) [–]

References

  1. 1. Xiong B, Richard T L, Kumar M. Integrated acidogenic digestion and carboxylic acid separation by nanofiltration membranes for the lignocellulosic carboxylate platform. J. Membrane Science. 2015;489: 275–283. DOI: 10.1016/j.memsci.2015.04.022
  2. 2. Xiao T, Wang P, Yang X, Cai X, Lu J. Fabrication and characterization of novel asymmetric polyvinylidene fluoride (PVDF) membranes by the nonsolvent thermally induced phase separation (NTIPS) method for membrane distillation applications. J. Membrane Science. 2015;489: 160–174.DOI: 10.1016/j.memsci.2015.03.081
  3. 3. Sawada S, Ursino C, Galiano F, Simone S, Drioli E, Figoli A. Effect of citrate-based non-toxic solvents on poly (vinylidene fluoride) membrane preparation via thermally induced phase separation. J. Membrane Science. 2015;493: 232–242. DOI: 10.1016/j.memsci.2015.07.003
  4. 4. Baker R W. Membrane Technology and Applications. 3rd ed. Chichester: John Wiley & Sons Ltd; 2012. 575p. DOI: 10.1002/9781118359686
  5. 5. Ma B, Qin A, Li X, Zhao X, He C. Structure and properties of chitin whisker reinforced chitosan membranes. International J. Biological Macromolecules. 2014;64: 341–346. DOI:10.1016/j.ijbiomac.2013.12.015
  6. 6. Bueno C Z., Dias A M A, de Sousa H J C, Braga M E M, Moraes A M. Control of the properties of porous chitosan-alginate membranes through the addition of different proportions of Pluronic F68. Materials Science and Engineering C 2014;44: 117–125. DOI: 10.1016/j.msec.2014.08.014
  7. 7. Loeb S, Sourirajan S. Sea water demineralization by means of an osmotic membrane. In: Advances in Chemistry. Vol. 38.America: ACS Publications; 1963. p. 117–132. DOI: 10.1021/ba-1963-0038.ch009
  8. 8. Wu P, Imai M. Novel biopolymer composite membrane involved with selective mass transfer and excellent water permeability. In: Ning R Y, editor. Advancing Desalination. Croatia: InTech; 2012. p. 57–81. DOI: 10.5772/50697
  9. 9. Torres F G, Troncoso O P, Piaggio F, Hijar A. Structure–property relationships of a biopolymer network: The eggshell membrane. Acta Biomaterialia. 2010;6: 3687–3693. DOI: 10.1016/j.actbio.2010.03.014
  10. 10. Kashima K, Imai M, Suzuki I. Superior molecular size screening and mass-transfer characterization of calcium alginate membrane. Desalination and Water Treatment. 2010;17: 143–149. DOI: 10.5004/dwt.2010.1710
  11. 11. Kashima K, Imai M. Dominant impact of the α-L-guluronic acid chain on regulation of the mass transfer character of calcium alginate membranes. Desalination and Water Treatment. 2011;34: 257–265. DOI: 10.5004/dwt.2011.2892
  12. 12. Michalak I, Mucha M. The release of active substances from selected carbohydrate biopolymer membranes. Carbohydrate Polymers. 2012;87: 2432–2438. DOI: 10.1016/j.carbpol.2011.11.013
  13. 13. Wu P, Imai M. Excellent dyes removal and remarkable molecular size rejection of novel biopolymer composite membrane. Desalination and Water Treatment. 2013;51: 5237–5247. DOI: 10.1080/19443994.2013.768836
  14. 14. Lakra R, Saranya R, Lukka Thuyavan Y, Sugashini S, Meera K M, Begum S, Arthanareeswaran G. Separation of acetic acid and reducing sugars from biomass derived hydrosylate using biopolymer blend polyethersulfone membrane. Separation and Purification Technology. 2013;118: 853–861. DOI: 10.1016/j.seppur.2013.08.023
  15. 15. Moraes M A, Cocenza D S, Vasconcellos F da C, Fraceto L F, Beppu M M. Chitosan and alginate biopolymer membranes for remediation of contaminated water with herbicides. J. Environmental Management. 2013;131: 222–227. DOI: 10.1016/j.jenvman.2013.09.028
  16. 16. Nomoto R, Imai M. Dominant role of acid-base neutralization process in forming chitosan membrane for regulating mechanical strength and mass transfer characteristics. J. Chitin and Chitosan Science. 2014;2: 197–204. DOI: 10.1166/jcc.2014.1055
  17. 17. Ma S, Chen Z, Qiao F, Sun Y, Yang X, Deng X, Cen L, Cai Q, Wu M, Zhang X, Gao P. Guided bone regeneration with tripolyphosphate cross-linked asymmetric chitosan membrane. J. Dentistry. 2014;42: 1603–1612. DOI: 10.1016/j.jdent.2014.08.015
  18. 18. Uragami T, Saito T, Miyata T. Pervaporative dehydration characteristics of an ethanol/water azeotrope through various chitosan membranes. Carbohydrate Polymers. 2015;120: 1–6. DOI: 10.1016/j.carbpol.2014.11.032
  19. 19. Alias S S, Ariff Z M, Mohamad A A. Porous membrane based on chitosan–SiO2 for coin cell proton battery. Ceramics International. 2015;41: 5484–5491. DOI: 10.1016/j.ceramint.2014.12.119
  20. 20. Puspasari T, Pradeep N, Peinemann K-V. Crosslinked cellulose thin film composite nanofiltration membranes with zero salt rejection. J. Membrane Science 2015;491: 132–137. DOI: 10.1016/j.memsci.2015.05.002
  21. 21. Livazovic S, Li Z, Behzad A R, Peinemann K-V, Nunes S P. Cellulose multilayer membranes manufacture with ionic liquid. J. Membrane Science. 2015;490: 282–293. DOI: 10.1016/j.memsci.2015.05.009
  22. 22. Zhang X, Lin B, Zhao K, Wei J, Guo J., Cui W, Jiang S, Liu D, Li J. A free-standing calcium alginate/polyacrylamide hydrogel nanofiltration membrane with high anti-fouling performance: Preparation and characterization. Desalination. 2015:365: 234–241. DOI: 10.1016/j.desal.2015.03.015
  23. 23. Patel A K. Chitosan: Emergence as potent candidate for green adhesive market. Biochemical Engineering J..2015; 102: 74–81. DOI: 10.1016/j.bej.2015.01.005
  24. 24. Bai H, Zhang H, He Y, Liu J, Zhang B, Wang J. Enhanced proton conduction of chitosan membrane enabled by halloysite nanotubes bearing sulfonate polyelectrolyte brushes. J. Membrane Science. 2014;454: 220–232. DOI: 10.1016/j.memsci.2013.12.005
  25. 25. Tasselli F, Mirmohseni A, Seyed Dorraji M S, Figoli A. Mechanical, swelling and adsorptive properties of dry–wet spun chitosan hollow fibers crosslinked with glutaraldehyde. Reactive and Functional Polymers. 2013;73: 218–223. DOI: 10.1016/j.reactfunctpolym.2012.08.007
  26. 26. Sun X, Wang Z, Kadouh H, Zhou K, The antimicrobial, mechanical, physical and structural properties of chitosan–gallic acid films. LWT - Food Science and Technology. 2014;57: 83–89. DOI: 10.1016/j.lwt.2013.11.037
  27. 27. Wanichapichart P, Bootluck W, Thopan P, Yu L D. Influence of nitrogen ion implantation on filtration of fluoride and cadmium using polysulfone/chitosan blend membranes. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 2014;326: 195–199. DOI: 10.1016/j.nimb.2013.10.091
  28. 28. Shenvi S, Ismail A F, Isloor A M. Preparation and characterization study of PPEES/chitosan composite membrane crosslinked with tripolyphosphate. Desalination. 2014;344: 90–96. DOI: 10.1016/j.desal.2014.02.026
  29. 29. Han F, Dong Y, Song A, Yin R, Li S. Alginate/chitosan based bi-layer composite membrane as potential sustained-release wound dressing containing ciprofloxacin hydrochloride. Applied Surface Science. 2014;311: 626–634. DOI: 10.1016/j.apsusc.2014.05.125
  30. 30. Karim Z, Mathew A P, Grahn M, Mouzon J, Oksman K. Nanoporous membranes with cellulose nanocrystals as functional entity in chitosan: Removal of dyes from water. Carbohydrate Polymers. 2014;112: 668–676. DOI: 10.1016/j.carbpol.2014.06.048
  31. 31. Dudek G, Gnus M, Turczyn R, Strzelewicz A, Krasowska M. Pervaporation with chitosan membranes containing iron oxide nanoparticles. Separation and Purification Technology. 2014;133: 8–15. DOI: 10.1016/j.seppur.2014.06.032
  32. 32. Kumar R, Isloor A M, Ismail A F. Preparation and evaluation of heavy metal rejection properties of polysulfone/chitosan, polysulfone/N-succinyl chitosan and polysulfone/N-propylphosphonyl chitosan blend ultrafiltration membranes. Desalination. 2014;350: 102–108. DOI: 10.1016/j.desal.2014.07.010
  33. 33. Sajjan A M, Premakshi H G, Kariduraganavar M Y. Synthesis and characterization of GTMAC grafted chitosan membranes for the dehydration of low water content isopropanol by pervaporation. J. Industrial and Engineering Chemistry. 2015;25: 151–161. DOI: 10.1016/j.jiec.2014.10.027
  34. 34. Bibi S, Yasin T, Hassan S, Riaz M, Nawaz M. Chitosan/CNTs green nanocomposite membrane: Synthesis, swelling and polyaromatic hydrocarbons removal. Materials Science and Engineering C. 2015;46: 359–365. DOI: 10.1016/j.msec.2014.10.057
  35. 35. Ji Y-L, An Q-F, Zhao F-Y, Gao C-J. Fabrication of chitosan/PDMCHEA blend positively charged membranes with improved mechanical properties and high nanofiltration performances. Desalination. 2015;357: 8–15. DOI: 10.1016/j.desal.2014.11.005
  36. 36. Premakshi H G, Ramesh K, Kariduraganavar M Y. Modification of crosslinked chitosan membrane using NaY zeolite for pervaporation separation of water–isopropanol mixtures. Chemical Engineering Research and Design. 2015;94: 32–43. DOI: 10.1016/j.cherd.2014.11.014
  37. 37. Santamaria M, Pecoraro C M, Quarto F D, Bocchetta P. Chitosan–phosphotungstic acid complex as membranes for low temperature H2–O2 fuel cell. J. Power Sources. 2015;276: 189–194. DOI: 10.1016/j.jpowsour.2014.11.147
  38. 38. Zhu J, Tian M, Zhang Y, Zhang H, Liu J. Fabrication of a novel “loose” nanofiltration membrane by facile blending with Chitosan–Montmorillonite nanosheets for dyes purification. Chemical Engineering J.. 2015;265: 184–193. DOI: 10.1016/j.cej.2014.12.054
  39. 39. Li Y-H, Cheng C-Y, Wang N-K, Tan H-Y, Tsai Y-J, Hsiao C-H, Ma D H-K, Yeh L-K. Characterization of the modified chitosan membrane cross-linked with genipin for the cultured corneal epithelial cells. Colloids and Surfaces B: Biointerfaces. 2015;126: 237–244. DOI: 10.1016/j.colsurfb.2014.12.029
  40. 40. Hegab H M, Wimalasiri Y, Ginic-Markovic M, Zou L. Improving the fouling resistance of brackish water membranes via surface modification with graphene oxide functionalized chitosan. Desalination. 2015;365: 99–107. DOI: 10.1016/j.desal.2015.02.029
  41. 41. Zhang D, Zhou W, Wei B, Wang X, Tang R, Nie J, Wang J. Carboxyl-modified poly (vinyl alcohol)-crosslinked chitosan hydrogel films for potential wound dressing. Carbohydrate Polymers. 2015;125: 189–199. DOI: 10.1016/j.carbpol.2015.02.034
  42. 42. Panda S R, Mukherjee M, De S. Preparation, characterization and humic acid removal capacity of chitosan coated iron-oxide-polyacrylonitrile mixed matrix membrane. J. Water Process Engineering. 2015;6: 93–104. DOI: 10.1016/j.jwpe.2015.03.007
  43. 43. Antunes B P, Moreira A F, Gaspar V M, Correia I J. Chitosan/arginine–chitosan polymer blends for assembly of nanofibrous membranes for wound regeneration. Carbohydrate Polymers. 2015;130: 104–112. DOI: 10.1016/j.carbpol.2015.04.072
  44. 44. Song K, Gao A, Cheng X, Xie K. Preparation of the superhydrophobic nano-hybrid membrane containing carbon nanotube based on chitosan and its antibacterial activity. Carbohydrate Polymers. 2015;130: 381–387. DOI:10.1016/j.carbpol.2015.05.023
  45. 45. Wang J, He R. Formation and evaluation of interpenetrating networks of anion exchange membranes based on quaternized chitosan and copolymer poly (acrylamide)/polystyrene. Solid State Ionics. 2015;278: 49–57. DOI: 10.1016/j.ssi.2015.05.017
  46. 46. Malini M, Thirumavalavan M, Yang W-Y, Lee J-F, Annadurai G. A versatile chitosan/ZnO nanocomposite with enhanced antimicrobial properties. International Journal of Biological Macromolecules. 2015;80: 121–129. DOI: 10.1016/j.ijbiomac.2015.06.036
  47. 47. Deuchi K, Kanauchi O, Imasato Y, Kobayashi E. Decreasing effect of chitosan on the apparent fat digestibility by rats fed on high-fat diet. Bioscience, Biotechnology, and biochemistry. 1994;58: 1613–1616. DOI: 10.1271/bbb.58.1613
  48. 48. Yao H-T, Huang S-Y, Chiang M-T. A comparative study on hypoglycemic and hypocholesterolemic effects of high and low molecular weight chitosan in streptozotocin-induced diabetic rats. Food and Chemical Toxicology. 2008;46: 1525–1534. DOI: 10.1016/j.fct.2007.12.012
  49. 49. Lu G, Kong L, Sheng B, Wang G, Gong Y, Zhang X. Degradation of covalently cross-linked carboxymethyl chitosan and its potential application for peripheral nerve regeneration. European Polymer J.. 2007;43: 3807–3818. DOI: 10.1016/j.eurpolymj.2007.06.016
  50. 50. Takahashi T, Imai M, Suzuki I. Water permeability of chitosan membrane involved in deacetylation degree control. Biochemical Engineering J.. 2007;36: 43–48. DOI: 10.1016/j.bej.2006.06.014
  51. 51. Takahashi T, Imai M, Suzuki I. Cellular structure in an N-acetyl-chitosan membrane regulate water permeability. Biochemical Engineering J.. 2008;42: 20–27. DOI: 10.1016/j.bej.2008.05.013
  52. 52. Santos C, Seabra P, Veleirinho B, Delgadillo I, Lopes da Silva J A. Acetylation and molecular mass effects on barrier and mechanical properties of shortfin squid chitosan membranes. European Polymer J.. 2006;42: 3277–3285. DOI: 10.1016/j.eurpolymj.2006.09.001
  53. 53. Ghosh A, Ali M A, Walls R. Modification of microstructural morphology and physical performance of chitosan films. International J. Biological Macromolecules. 2010;46: 179–186. DOI: 10.1016/j.ijbiomac.2009.11.006
  54. 54. Jin J, Song M, Hourston D J. Novel chitosan-based films cross-linked by genipin with improved physical properties. Biomacromolecules. 2004;5: 162–168. DOI: 10.1021/bm034286m
  55. 55. Remuñán-López C, Bodmeier R. Mechanical, water uptake and permeability properties of crosslinked chitosan glutamate and alginate films. J. Controlled Release. 1997;44: 215–225. DOI: 10.1016/S0168-3659 (96)01525-8
  56. 56. Lee Y M, Nam S Y, Woo D J. Pervaporation of ionically surface crosslinked chitosan composite membranes for water-alcohol mixtures. J. Membrane Science. 1997;133: 103–110. DOI: 10.1016/S0376-7388 (97)00089-6
  57. 57. Devi D A, Smitha B, Sridhar S, Aminabhavi T M. Pervaporation separation of isopropanol/water mixtures through crosslinked chitosan membranes. J. Membrane Science. 2005;262: 91–99. DOI: 10.1016/j.memsci.2005.03.051
  58. 58. Cottrell I W, Kovacs P. Alginate. In: Davidson R L, editor.Handbook of water-soluble gums and resins. New York: McGraw-HillInc.;1980. P. 2-1–2-43.
  59. 59. Baffoun A, Viallier P, Dupuis D, Haidara H. Drying morphologies and related wetting and impregnation behaviours of ‘sodium-alginate/urea’ inkjet printing thickeners. Carbohydrate Polymers. 2005; 61: 103–110. DOI: 10.1016/j.carbpol.2005.03.018
  60. 60. Richardson J C, Dettmar P W, Hampson F C, Melia C D. Oesophageal bioadhesion of sodium alginate suspensions: 2. Suspension behaviour on oesophageal mucosa.European J. Pharmaceutical Sciences. 2005; 24: 107–114. DOI: 10.1016/j.ejps.2004.10.001
  61. 61. Rescignano N, Fortunati E, Armentano I, Hernandez R, Mijangos C, Pasquino R, Kenny J M. Use of alginate, chitosan and cellulose nanocrystals as emulsion stabilizers in the synthesis of biodegradable polymeric nanoparticles. J. Colloid Interface Science. 2015; 445: 31–39. DOI: 10.1016/j.jcis.2014.12.032
  62. 62. Yang Y, Campanella O H, Hamaker B R, Zhang G, Gu Z. Rheological investigation of alginate chain interactions induced by concentrating calcium cations. Food Hydrocolloids. 2013; 30: 26–32. DOI: 10.1016/j.foodhyd.2012.04.006
  63. 63. Li J, He J, Huang Y, Li D, Chen X. Improving surface and mechanical properties of alginate films by using ethanol as a co-solvent during external gelation. Carbohydrate Polymers. 2015; 123: 208–216. DOI: 10.1016/j.carbpol.2015.01.040
  64. 64. Ha T L B, Quan T M, Vu D N, Si D M. Naturally Derived Biomaterials: Preparation and Application. In: Andrades J A, editor. Regenerative Medicine and Tissue Engineering. Croatia: InTech; 2013. p. 247–274. DOI: 10.5772/55668
  65. 65. Kashima K, Imai M. Impact factors to regulate mass transfer characteristics of stable alginate membrane performed superior sensitivity on various organic chemicals. Procedia Engineering. 2012; 42: 964–977. DOI: 10.1016/j.proeng.2012.07.490
  66. 66. Toti U S, Aminabhavi T M. Different viscosity grade sodium alginate and modified sodium alginate membranes in pervaporation separation of water + acetic acid and water + isopropanol mixtures. J. Membrane Science. 2004;228: 199–208. DOI: 10.1016/j.memsci.2003.10.008
  67. 67. Kalyani S, Smitha B, Sridhar S, Krishnaiah A. Pervaporation separation of ethanol–water mixtures through sodium alginate membranes. Desalination. 2008;229: 68–81. DOI: 10.1016/j.desal.2007.07.027
  68. 68. Saraswathi M, Madhusudhan Rao K, Prabhakar M N, Prasad C V, Sudakar K, Naveen Kumar H M P, Prasad M, Chowdoji Rao K, Subha M C S. Pervaporation studies of sodium alginate (SA)/dextrin blend membranes for separation of water and isopropanol mixture. Desalination. 2011;269: 177–183. DOI: 10.1016/j.desal.2010.10.059
  69. 69. Li Y, Jia H, Cheng Q, Pan F, Jiang Z. Sodium alginate–gelatin polyelectrolyte complex membranes with both high water vapor permeance and high permselectivity. J. Membrane Science. 2011;375: 304–312. DOI: 10.1016/j.memsci.2011.03.058
  70. 70. Taşkın G, Şanlı O, Asman G. Swelling assisted photografting of itaconic acid onto sodium alginate membranes. Applied Surface Science. 2011;257: 9444–9450. DOI: 10.1016/j.apsusc.2011.06.030
  71. 71. Chen J H, Liu Q L, Hu S R, Ni J C, He Y S. Adsorption mechanism of Cu (II) ions from aqueous solution by glutaraldehyde crosslinked humic acid-immobilized sodium alginate porous membrane adsorbent. Chemical Engineering J.. 2011;173: 511–519. DOI: 10.1016/j.cej.2011.08.023
  72. 72. Li Y, Jia H, Pan F, Jiang Z, Cheng Q. Enhanced anti-swelling property and dehumidification performance by sodium alginate–poly (vinyl alcohol)/polysulfone composite hollow fiber membranes. J. Membrane Science. 2012;407–408: 211–220. DOI: 10.1016/j.memsci.2012.03.049
  73. 73. Nigiz F U, Dogan H, Hilmioglu N D. Pervaporation of ethanol/water mixtures using clinoptilolite and 4A filled sodium alginate membranes. Desalination. 2012;300: 24–31. DOI: 10.1016/j.desal.2012.05.036
  74. 74. Sajjan A M, Jeevan Kumar B K, Kittur A A, Kariduraganavar M Y. Novel approach for the development of pervaporation membranes using sodium alginate and chitosan-wrapped multiwalled carbon nanotubes for the dehydration of isopropanol. J. Membrane Science. 2013;425–426: 77–88. DOI: 10.1016/j.memsci.2012.08.042
  75. 75. Flynn E J, Keane D, Holmes J D, Morris M A. Unusual trend of increasing selectivity and decreasing flux with decreasing thickness in pervaporation separation of ethanol/water mixtures using sodium alginate blend membranes. J. Colloid and Interface Science. 2012;370: 176–182. DOI: 10.1016/j.jcis.2011.12.022
  76. 76. Shi J, Shi J, Du C, Chen Q, Cao S. Thermal and pH dual responsive alginate/CaCO3 hybrid membrane prepared under compressed CO2. J. Membrane Science. 2013;433: 39–48. DOI: 10.1016/j.memsci.2013.01.021
  77. 77. Chen J H, Xing H T, Guo H X, Li G P, Weng W, Hu S R. Preparation, characterization and adsorption properties of a novel 3-aminopropyltriethoxysilane functionalized sodium alginate porous membrane adsorbent for Cr (III) ions. J. Hazardous Materials. 2013;248–249: 285–294. DOI: 10.1016/j.jhazmat.2013.01.042
  78. 78. Zhu Y, Wang Z, Zhang C, Wang J, Wang S. A novel membrane prepared from sodium alginate cross-linked with sodium tartrate for CO2 capture. Chinese J. Chemical Engineering. 2013;21: 1098–1105. DOI: 10.1016/S1004-9541 (13)60574-1
  79. 79. Adoor S G, Rajineekanth V, Nadagouda M N, Rao K C, Dionysiou D D, Aminabhavi T M. Exploration of nanocomposite membranes composed of phosphotungstic acid in sodium alginate for separation of aqueous–organic mixtures by pervaporation. Separation and Purification Technology. 2013;113: 64–74. DOI: 10.1016/j.seppur.2013.03.051
  80. 80. Zhang W, Xu Y, Yu Z, Lu S, Wang X. Separation of acetic acid/water mixtures by pervaporation with composite membranes of sodium alginate active layer and microporous polypropylene substrate. J. Membrane Science. 2014;451: 135–147. DOI: 10.1016/j.memsci.2013.09.027
  81. 81. Gao C, Zhang M, Ding J, Pan F, Jiang Z, Li Y, Zhao J. Pervaporation dehydration of ethanol by hyaluronic acid/sodium alginate two-active-layer composite membranes. Carbohydrate Polymers. 2014;99: 158–165. DOI: 10.1016/j.carbpol.2013.08.057
  82. 82. Kuila S B, Ray S K. Dehydration of dioxane by pervaporation using filled blend membranes of polyvinyl alcohol and sodium alginate. Carbohydrate Polymers. 2014;101: 1154–1165. DOI: 10.1016/j.carbpol.2013.09.086
  83. 83. Kuila S B, Ray S K. Separation of benzene–cyclohexane mixtures by filled blend membranes of carboxymethyl cellulose and sodium alginate. Separation and Purification Technology. 2014;123: 45–52. DOI: 10.1016/j.seppur.2013.12.017
  84. 84. Yang J-M, Wang N-C, Chiu H-C. Preparation and characterization of poly (vinyl alcohol)/sodium alginate blended membrane for alkaline solid polymer electrolytes membrane. J. Membrane Science. 2014;457: 139–148. DOI: 10.1016/j.memsci.2014.01.034
  85. 85. Pasini Cabello S D, Mollá S, Ochoa N A, Marchese J, Giménez E, Compañ V. New bio-polymeric membranes composed of alginate-carrageenan to be applied as polymer electrolyte membranes for DMFC. J. Power Sources. 2014;265: 345–355. DOI: 10.1016/j.jpowsour.2014.04.093
  86. 86. Cao K, Jiang Z, Zhao J, Zhao C, Gao C, Pan F, Wang B, Cao X, Yang J. Enhanced water permeation through sodium alginate membranes by incorporating graphene oxides. J. Membrane Science. 2014;469: 272–283. DOI: 10.1016/j.memsci.2014.06.053
  87. 87. Yoo S M, Ghosh R. Fabrication of alginate fibers using a microporous membrane based molding technique. Biochemical Engineering J.. 2014;91: 58–65. DOI: 10.1016/j.bej.2014.07.006
  88. 88. Kamoun E A, Kenawy E-R S, Tamer T M, El-Meligy M A, Eldin M S M. Poly (vinyl alcohol)-alginate physically crosslinked hydrogel membranes for wound dressing applications: Characterization and bio-evaluation. Arabian J. Chemistry. 2015;8: 38–47. DOI: 10.1016/j.arabjc.2013.12.003
  89. 89. Li J, He J, Huang Y, Li D, Chen X. Improving surface and mechanical properties of alginate films by using ethanol as a co-solvent during external gelation. Carbohydrate Polymers. 2015;123: 208–216. DOI: 10.1016/j.carbpol.2015.01.040
  90. 90. Soazo M, Báez G, Barboza A, Busti P A, Rubiolo A, Verdini R, Delorenzi N J. Heat treatment of calcium alginate films obtained by ultrasonic atomizing: Physicochemical characterization. Food Hydrocolloids. 2015;51: 193–199. DOI: 10.1016/j.foodhyd.2015.04.037
  91. 91. Zhao K, Zhang X, Wei J, Li J, Zhou X, Liu D, Liu Z, Li J. Calcium alginate hydrogel filtration membrane with excellent anti-fouling property and controlled separation performance. J. Membrane Science. 2015;492: 536–546. DOI: 10.1016/j.memsci.2015.05.075
  92. 92. Jie G, Kongyin Z, Xinxin Z, Zhijiang C, Min C, Tian C, Junfu W. Preparation and characterization of carboxyl multi-walled carbon nanotubes/calcium alginate composite hydrogel nano-filtration membrane. Materials Letters. 2015;157: 112–115. DOI: 10.1016/j.matlet.2015.05.080
  93. 93. Kirdponpattara S, Khamkeaw A, Sanchavanakit N, Pavasant P, Phisalaphong M. Structural modification and characterization of bacterial cellulose–alginate composite scaffolds for tissue engineering. Carbohydrate Polymers. 2015;132: 146–155. DOI: 10.1016/j.carbpol.2015.06.059
  94. 94. Shao W, Liu H, Liu X, Wang S, Wu J, Zhang R, Min H, Huang M. Development of silver sulfadiazine loaded bacterial cellulose/sodium alginate composite films with enhanced antibacterial property. Carbohydrate Polymers. 2015;132: 351–358. DOI: 10.1016/j.carbpol.2015.06.057
  95. 95. Uragami T, Banno M, Miyata T. Dehydration of an ethanol/water azeotrope through alginate-DNA membranes cross-linked with metal ions by pervaporation. Carbohydrate Polymers. 2015;134: 38–45. DOI: 10.1016/j.carbpol.2015.07.054
  96. 96. Haug A, Larsen B, Smidsrød O. A study of the constitution of alginic acid by partial acid hydrolysis. Acta Chemica Scandinavica. 1966;20: 183–190. DOI: 10.3891/acta.chem.scand.20-0183
  97. 97. Haug A, Larsen B, Smidsrød O. Uronic acid sequence in alginate from different sources. Carbohydrate Research. 1974;32: 217–225. DOI: 10.1016/S0008-6215 (00)82100-X
  98. 98. Gacesa P. Alginates. Carbohydr. Polym. 1988;8: 161–182. DOI: 10.1016/0144-8617 (88)90001-X
  99. 99. Draget K I, Smidsrød O, Skjåk-Bræk G. Alginates from algae. In: Steinbuchel A, Rhee S K, editors. Polysaccharides and Polyamides in the Food Industry, Properties, Production and Patents. Weinheim: Wiley–VCH; 2005. P. 1-30. DOI: 10.1002/3527600035.bpol6008
  100. 100. Grant G T, Morris E R, Rees D A, Smith P J C, Thom D. Biological interactions between polysaccharides and divalent cations: The egg-box model. FEBS Letters. 1973;32: 195–198. DOI: 10.1016/0014-5793 (73)80770-7
  101. 101. Kashima K, Imai M. Advanced membrane material from marine biological polymer and sensitive molecular-size recognition for promising separation technology. In: Ning R Y, editor. Advancing Desalination. Croatia: InTech; 2012. p. 3–36. DOI: 10.5772/50734
  102. 102. Bitter T, Muir H M. A modified uronic acid carbazole reaction. Analytical Biochemistry. 1962;4: 330–334. DOI: 10.1016/0003-2697 (62)90095-7
  103. 103. Anzai H, Uchida N, Nishide E. Determination of D-mannuronic to L-guluronic acids ratio in acid hydrolysis of alginate under improved conditions. Nippon Suisan Gakkaishi. 1990;56: 73–81. DOI: 10.2331/suisan.56.73
  104. 104. Anzai H, Uchida N, Nishide E. Comparative studies of colorimetric analysis for uronic acids. Bulletin of the College of Agriculture and Veterinary Medicine Nihon University. 1986;43: 53–56 (in Japanese).
  105. 105. Wilke C R, Chang P. Correlation of diffusion coefficients in dilute solutions. A. I. Ch. E. J. 1955;1: 264–270. DOI: 10.1002/aic.690010222
  106. 106. Smidsrød O. Molecular basis for some physical properties of alginates in the gel state. Faraday Discussions of the Chemical Society.1974; 57: 263–274. DOI: 10.1039/DC9745700263
  107. 107. Donati I, Paoletti S. Material Properties of Alginates, In: B H. A. Rehm editor, Alginates: Biology and Applications. Berlin: Springer; 2009. p. 1–53. DOI: 10.1007/978-3-540-92679-5_1
  108. 108. So M T, Eirich F R, Strathmann H, Baker R W. Preparation of Asymmetric Loeb-Sourirajan Membranes. J. Polymer Science: Polymer Letters Edition. 1973;11: 201–205. DOI: 10.1002/pol.1973.130110311

Written By

Keita Kashima, Ryuhei Nomoto and Masanao Imai

Submitted: 16 May 2015 Reviewed: 16 November 2015 Published: 09 March 2016