Perspective Chapter: Nanocomposites – Unlocking the Potentials for Diverse Applications

Abstract

Nanocomposites (NCS) are advanced materials consisting of a matrix material infused with nanoscale particles or fillers, exhibiting exceptional properties such as high conductivity, strength, reactivity, and thermal/electrical characteristics. This article provides an overview of nanocomposites, including their properties, preparation methods, and diverse applications across industries like aerospace, automotive, biomedical, energy, water purification, and environmental bioremediation. Various techniques for nanocomposite preparation, such as electrospinning, are discussed along with their potential for producing tailored materials with enhanced properties. Challenges and future directions in nanocomposite research, including scalability and cost considerations, are highlighted, along with emerging trends and prospects in nanotechnology applications.

1. Introduction

Nanocomposites (NCS) are hybrid materials consisting of matrix material (typically a polymer, metal, or semiconductor) infused with nanoscale particle or filler (i.e. nanoparticles or nanofillers). These materials can be engineered through various techniques such as solution blending (wet impregnation), melt mixing, and in situ polymerization [1]. Nanocomposites possess unique features such as high conductivity, high strength and reactivity, and good thermal and electrical properties [2, 3]. NCS find applications in various fields of studies such as biomedical, electronics, regenerative medicine, food packaging, aerospace, biosensors, drug delivery, tissue engineering, and environmental remediation. Nanocomposite research is gaining interest for its versatility and superior properties compared to their corresponding single materials. These materials, particularly carbon-based material like carbon nanotubes (CNTs) and graphene nanoplates, have been extensively studied for their electrical, mechanical, and thermal properties [4]. Polymer/inorganic nanocomposites are widely used in dielectric materials due to their exceptional physical and mechanical characteristics, as well as unique electrical, thermal, sound, light, and magnetic properties [5].

2. Properties of nanocomposites

Nanocomposites represent a revolutionary class of materials with a multitude of properties that surpass traditional materials in several key aspects. These advanced materials, infused with nanoscale particles or fillers, exhibit enhanced mechanical strength, improved thermal stability, high electrical conductivity, and tailored optical properties, among others. Their lightweight nature, coupled with high specific strength and chemical resistance, makes them indispensable in industries ranging from aerospace and automotive to electronics, biomedical, and environmental applications. In this context, exploring the properties of nanocomposites unveils a world of possibilities for innovative solutions and cutting-edge advancements in modern materials science (Figure 1). Well-dispersed and aligned structures enhance load transfer, heat dissipation, and charge transport [6, 7].

Figure 1.

Illustration of properties of nanocomposites.

3. Preparation of nanocomposites

Nanocomposites can be prepared using various methods such as in situ polymerization, sol-gel process, chemical vapor deposition, melt mixing, solution blending, colloidal and precipitation approaches, electrospinning, and template synthesis [8, 9]. Their preparation involves various methods aimed at dispersing nanoparticles evenly throughout the matrix to enhance mechanical, thermal, electrical, or other properties (Figure 2). Polymer matrix nanocomposites can be produced either by chemical or by mechanical processes, with melt intercalation being a commonly used method for synthesis of thermoplastic polymer nanocomposites [10]. The incorporation of nanomaterials into polymer matrices allows for the development of advanced materials with unique properties [11]. A specific preparation method for a nanocomposite material with self-healing properties involves the reaction of a polyol and a polyisocyanate to prepare a polyurethane matrix, adding self-healing functional molecules, and then adding a filler to obtain the nanocomposite material [12]. Nanocomposites can be prepared using various polymer matrices such as low-density polyethylene, high-density polyethylene, polypropylene, polyvinyl chloride, polylactic acid, Nylon 6, and polyether ether ketone (PEEK), with different combinations of nanomaterials [13]. Another preparation method for a polymer nanocomposite involves dissolving polyvinyl chloride, polyethylene, and a polyvinyl chloride-polyethylene block copolymer, and then adding a surfactant, a light transparency enhancing material, and a reinforcing material to the solution.

Figure 2.

Methods for nanocomposites preparation.

4. Applications of nanocomposites

Nanocomposites have varied applications in biomedical, aerospace, environmental bioremediation, water purification, energy storage, and automobile industries requiring high mechanical strength, lightweight, biocompatibility, biodegradability, durability, and heat resistance. These properties showcase their versatile utility across the three industries.

4.1 Aerospace industry

Nanocomposites are desirable materials for aerospace applications due to their unique properties. They offer high strength, resistance to fatigue and corrosion, thermal stability, and thermal conductivity. Additionally, nanocomposites provide design flexibility, lower assembly costs, and lightweight components without compromising reliability. The incorporation of nanocarbon nanofillers, such as carbon nanotubes, graphene, and nanodiamond, into polymer matrices enhances the corrosion resistance of the materials. The dispersion of nanocarbon nanoparticles in the matrices creates an electron-conducting network, facilitating charge transport and improving corrosion resistance. The formation of tortuous diffusion pathways due to the arrangement of nanofillers in the matrices further enhances the corrosion protection properties. Epoxy has been found to be a superior corrosion-resisting polymer, and carbon nanotubes with a loading of up to 7% weight in the epoxy matrix are desirable for corrosion resistance. Thorough research efforts are still needed to design high-performance nanocomposites that can completely replace metal components in the aerospace industry [14, 15].

4.2 Automotive industry

Nanocomposites, prized for superior thermal and mechanical properties, are extensively applied in aerospace, automotive, chemical, and transport industries [16, 17]. First employed in automotive production in 1991 for Toyota Camry timing belt covers, these nanocomposites, incorporating high-strength steel, aluminum, carbon fiber, and plastics, boost strength by 100%. They enable the creation of lighter and sturdier automobile components, including frames, chassis, body mountings, and engine parts. Additionally, the use of aluminum nanofluids in fuel combustion enhances total heat while curbing smoke and nitrous oxide concentrations in engine emissions [18, 19].

4.3 Biomedical applications

Biomedical nanocomposites, applied in drug delivery, antimicrobial properties, tissue engineering, and more, play a key role in orthopedic drug delivery, utilizing vessels near the bone [20, 21, 22]. Inorganic nanocomposites like calcium phosphate (CaPO₄) and hydroxyapatite (HAp) provide mechanical strength for orthopedic implants and deliver bioactive molecules. A 50% calcium sulphate (CaSO₄) and 50% nanocrystalline apatite nanocomposite are designed for orthopedic drug delivery [23], mimicking the natural body environment for enhanced properties and biological activities [24]. Biomaterials based on nanocomposites, resembling the natural extracellular matrix, are explored for tissue engineering scaffolds with superior mechanical performance, controlled degradation, biocompatibility, and efficient stimuli transduction [25]. Diverse forms of tissue scaffolds ensure uniform cell distribution, nutrient diffusion, and organized cell growth. Carbon-based nanocomposites, such as carbon nanotubes (CNTs), graphene, and carbon quantum dots (CQDs), have been employed as sensing materials for the detection of biomarkers in biomedical applications due to their high surface-to-volume ratio, high electrical conductivity, chemical stability, and biocompatibility [26].

4.4 Energy sector

Nanocomposites have various uses in the energy sector. They are used in the development of multifunctional materials with improved electrical, physical, and chemical properties [27]. In particular, nanocomposites are applied in energy generation and energy storage, making them essential for addressing the growing energy demand [28]. Metal oxides, nanoclays, carbon nanotubes, and graphenes are commonly used as nanofillers in nanocomposites for energy applications [29]. Additionally, biobased nanocomposites, derived from natural renewable materials such as nanocellulose, lignin, and chitosan, are being explored for their potential in energy storage devices [30]. Nanocellulose and lignin-based electrodes have shown excellent electrochemical properties for batteries, while nanocellulose, lignin, and chitosan-based electrodes have exhibited promising electrochemical properties for supercapacitors. These low-cost and environmentally friendly nanocomposites offer a sustainable solution for energy storage.

4.5 Water purification

Nanocomposites can be used as effective adsorbents for dyes and hazardous metal ions enrichment from wastewater [31]. Nanocomposites, specifically MXene-based nanocomposites, have demonstrated the capability to adsorb various heavy contaminants, particularly metals such as chromium, copper, lead, and mercury [32]. Nanocomposite-based adsorbents have emerged as advanced tools for the effective removal of heavy metal ions and dyes from wastewater due to their characteristic features like affinity of metal ions, higher surface-to-volume ratio, and smaller size [33]. Nanocomposite membranes, incorporating nanoscale materials like carbon nanotubes, graphene oxide, metal oxides, and nanoparticles, have been developed for advanced water purification techniques such as microfiltration, ultrafiltration, nanofiltration, and reverse osmosis. These membranes efficiently remove contaminating microbes, heavy metals, hazardous dyes, and other xenobiotic compounds [34].

4.6 Environmental bioremediation

Nanocomposites have various uses in bioremediation. They are used for the efficient and eco-friendly removal of synthetic dyes from wastewater, offering a sustainable and cost-effective solution [35]. Nanoparticles can be coated with catalytic ligands, providing maximum effective surface area and good adsorbing properties, and they can be coupled with microbes to accelerate the remediation process of pollutants [36].

5. Challenges and future directions in nanocomposite research

The current challenges in nanocomposite are multifaceted; however, two outstanding issues are scalability and cost considerations, with scale-up issues and cost considerations becoming the major challenges. Nanocomposites face challenges in achieving consistent size and dispersity for use in biomedical applications [37]. Poor interfacial bonding hinders property enhancements, and industrial production faces challenges like aggregation, contamination, degradation, and low yield [38]. To enhance biocompatibility, improve mechanical properties, and reduce wear and corrosion, focused nanomanufacturing research is necessary. Reproducible large-batch nanoparticle synthesis can be achieved through strategies like multiparameters iterative chemistry, manufacturing, and controls (CMC) optimization, microfluidics systems, and computer software [39, 40]. Nanocomposites offer cost savings and hold potential for reducing energy consumption and environmental emissions in the automotive industry and enhancing efficiency in solar energy applications. Cost optimization is essential for competitiveness in nano-object manufacturing process [41, 42].

A framework that evaluates nanotechnology materials and design was conceived by Shalhevet and Haruvy [43]. Engineers optimize designs by considering economic factors and found costless nanofillers to improve trapping properties in polymer nanocomposites for electrical insulating materials. Semiconductor and nanocomposite industries generate challenging environmental waste, requiring more efficient recycling methods [44]. Understanding engineered nanomaterials is crucial for safer development. Life cycle analysis and green nanotechnology offer sustainable approaches. Micro/nanomotors enhance traditional remediation methods, emphasizing the need for robust nanotechnology regulations [45, 46, 47, 48, 49].

6. Emerging trends and future prospects

Nanoscience and nanotechnology have diverse applications across industries. Solid-state gas sensors, crucial in space exploration and biomedicine, benefit from durable nanocomposites enhancing properties like strength, wear resistance, and electron transfer [50]. In sectors such as pollutant degradation and aerospace, nanocomposites play vital roles [51]. Bio-renewable/sustainable nanocomposites, synthesized through environmentally friendly methods like plant-mediated synthesis, are gaining popularity [52, 53, 54]. Innovative techniques like mechanochemistry, flow chemistry, and laser synthesis, along with microwave-assisted methods, advance the preparation of nanomaterials for applications like water purification [55, 56]. Nanocomposites serve various purposes. In the automotive industry, they excel in brakes, engine covers, and tires [57]. Aeronautics benefits from their versatile mechanical, thermal, electrical, optical, and biodegradable features [55]. Polymeric nanocomposites, valued for adaptability and biocompatibility, find applications in healthcare, medicine, microelectronics, and chemical and mechanical engineering. The aerospace sector requires anticorrosion polymer/carbonaceous nanocomposites with corrosion resistance and electron conduction properties [58, 59].

7. Conclusion

Nanocomposites represent a promising class of materials with a wide range of applications due to their unique properties and versatility. They offer solutions for challenges in industries, such as aerospace, automotive, biomedical, energy, water purification, and environmental bioremediation, providing high mechanical strength, lightweight structures, biocompatibility, and enhanced functionalities. Despite challenges related to scalability and cost, ongoing research and innovative techniques are paving the way for the development of advanced nanocomposites with improved properties and performance. Future prospects in nanotechnology continue to evolve, with a focus on sustainable and eco-friendly synthesis methods, novel applications, and enhanced material designs to address global challenges.

Author contributions

All authors contributed equally to the development of the manuscript.

Funding

The authors declare that there are no pertinent financial or non-financial conflicts of interest to disclose.

Competing interests

There is no competing interest.