Eco-friendly Polymer Nanocomposites

This chapter aims at exploring the revolutionary field of nanotechnology and some of its promising aspects in polymer nanocomposites in view of preparation, characterization, materials properties, and processing of polymer layered silicate nanocomposites. These materials are attracting considerable interest in polymer science research. Polymer layered silicate nanocomposites are an important class of hybrid, organic/inorganic materials with substantially improved mechanical, thermal, and thermomechanical properties in comparison to pristine polymers. In addition, they also show superior ultraviolet (UV) as well as chemical resistance and are widely being investigated for improving gas barrier and flame retardant properties. Hectorite and montmorillonite are among the most commonly used smectite-type layered silicates for the preparation of polymer–clay nanocomposites. Smectites are a valuable mineral class for industrial applications due to their high cation exchange capacities, surface area, surface reactivity, adsorptive properties, and, in the case of hectorite, high viscosity and transparency in solution. A wide range of polymer matrices are explored for the preparation of polymer–clay nanocomposites, however, this chapter deals with special emphasis on biodegradable polymers––cellulose and natural rubber. Also, the chapter describes the common synthetic techniques in producing polymeric layered silicate nanocomposites, its properties, and applications.

The advent of nanotechnology has provided new insights of applications of well-known materials due to the exceptional properties owing to the nanoscale. As an example, nanocomposites based on polymer matrix and nanoscale fillers have appeared as good candidates in a broad range of applications. Such scenery can be credited to the use of new and multifunctional fillers that provide distinct and substantial features to the nanocomposites. Recent trends on the nanocomposites field show that crystalline biopolymers, such as cellulose, chitin, and starch, are an excellent source of fillers, especially nanocrystals like fibrils, whiskers, and platelets. The incorporation of such fillers in different matrices (e.g., crosslinked polymeric network) has demonstrated outstanding improvement of several properties, such as mechanical, water uptake capacity, thermal, optical, etc. Furthermore, crystals, fibrils and whiskers can induce desirable properties in the final materials (e.g., solute retention or release, crystallinity, biodegradability, biocompatibility, antibacterial activity, etc.). This chapter condenses the relevant works regarding the preparation of polysaccharide-based crystals, whiskers, and fibrils, their application in the development of hydrogel nanocomposites as well as the future trends of this area.

Lignin, the second most abundant natural polymer, has shown its immense potential as sustainable resources for the synthesis of nanocomposites. This chapter reviewed recent developments related to lignin-based nanocomposites, including the fabrication, properties, and applications of nanocomposites based on lignin and its derivatives. We introduced nanocomposites combining physical and chemical properties of lignin and organic materials such as biopolymer and synthetic polymer, and we discussed lignin-based metallic nanocomposites with preferable property and catalytic performance. Furthermore, lignin-based carbonaceous nanocomposites exhibiting enhanced electrical properties were illustrated. Other lignin-based nanocomposites were also presented in this chapter.

Nanocellulose (NC) has been attracting a great deal of interest as promising candidates for bionanocomposite due to their appealing intrinsic properties, such as low density, high surface area, and mechanical strength. In view of countless publications on nanocellulose composites already, this chapter concentrates on application of nanocellulose for reinforcing shape-memory composites. Shape-memory composites enable high-recovery stress levels and various functions due to their different components. The shape-memory behavior is also dependent on the size, shape, and concentration of the fillers. The effect of nanocellulose in these composites is determined by different shape-memory switches and interactions between nanocellulose and matrices. A challenge of using NC in shape-memory composites is the lack of compatibility between hydrophobic matrices and hydrophilic NCs. Various chemical modification methods have been explored to address this hurdle. In this chapter, we summarized the effect of nanocellulose on the deformation mechanism of shape-memory materials, with a particular focus on thermo- and water-sensitive switches. The application of shape-memory composites based on nanocellulose is also discussed.

Recently, nano-products play a dominant role in global manufacturing, and still in the not-so-distance future. Whereas new applications are being investigated everyday in many areas, e.g., agriculture, lignocellulosic products, food, nano-reactive membranes for water purification, nano-catalysts for air-purification, for water treatment, nanomaterials-based solar cells, as well as nano-coatings which are finding use in corrosion-resistance, dirt repellency, water repellency, thermal insulation, and antimicrobial applications. This paper reviews recent researches on utilizing nano-tech materials in production of high performance paper sheets. The highlight on our suggestions for production process of safety paper sheets from heterocyclic nanoparticles is also reported.

Bionanocomposites are emerging nanostructure hybrid materials composed of natural polymers and inorganic solids. Bionanocomposites became a subject of intensive research owing to their inherent properties such as nontoxicity, biocompatibility, biodegradability as well as their improved structural and functional properties. Among these bionanocomposites, chitosan-based nanocomposites have attracted a great deal of attention especially in biomedical field. Globally, chitosan is the second most bountiful natural polymer following cellulose. Chitosan is a biocompatible and biodegradable polymer possessing unique structural, chemical, and biological properties. The last decade has witnessed enormous multidisciplinary research focused on improving the properties of chitosan and its derivatives. As a result, several chitosan-based nanocomposites with enhanced physical and chemical properties have been developed in eco-friendly and cost-effective manner. This chapter provides an overview on different aspects of chitosan including its properties and modifications, and focuses on chitosan-based nanocomposites. Important biomedical applications of chitosan-based nanocomposites are also discussed in this chapter including tissue engineering, wound healing, tissue regeneration, drug delivery, and biosensors.

Graphene, a monolayer sp² hybridized carbon atom, received worldwide attention due to its extraordinary physical, chemical, thermal, and electrical properties. In recent years, the development of nanoscale dispersion techniques using graphene particles in a polymer matrix has been crowned a new and interesting horizon in material science. Graphene-based polymer nanocomposites reveal superior mechanical and thermal properties compared with the conventional graphite-based composites or neat polymers which are obtained through very low filler loadings in the polymer matrix. Graphene derivatives as unique nanofillers are used in the production of lightweight, low cost, and high-performance polymer nanocomposites with a wide range of applications, such as fuel cells, supercapacitors, solar cells, sensors, and lightweight gasoline tanks. This chapter reviews the preparation methods of graphene-based polymer nanocomposites, their characteristics, and their wide range of potential applications in technological fields.

Natural nanoscale materials can be used in many applications like packaging industry. The main reason is to provide packaging which would protect the food from dust, gases, light, pathogens, and moisture. These materials are mainly safe, inert, cheap to produce, easy to dispose, and reuse. In addition, the characteristics of these nanocomposites such as mechanical, electrical, thermal, optical, and electrochemical properties will differ markedly from that of the component materials. One of the most practical uses of nanocomposites in the food packaging is adding the nanosized components to the traditional packaging materials such as metal, glass, paper, various synthetic plastics like PE, PP, PS, PVC. Also, the use of nanofiller materials in the biofilm preparation has been subjected in the many recent studies. Therefore, this chapter is an attempt to introduce various bionanocomposites to readers and provide a general overview of these natural nanopolymer applications in the food packaging industry as well as some practical examples. In effect, nanopackaging materials were developed by clay minerals, e.g., montmorriolonite, in 1986 and are still being grown using many different natural polymers. However, natural nanopolymer applications in the packaging industry can be organized around the main topics, to introduce nanocomposite organic/inorganic materials and to introduce some good examples to produce films, coatings, etc. Detailed discussions about each of these topics are also considered in this chapter.

Magnetic separation in water remediation processes is of great interest in current environmental technologies. An important aspect in this field has been the development of efficient sorbents for water purification units, namely by exploiting other functionalities that might originate more sustainable technologies. This chapter describes the state-of-art on the chemical preparation of magnetic sorbents comprising inorganic particles and biopolymer matrices. Fundamental aspects related to nanoparticle synthesis of iron oxides and nanomagnetism will be first addressed. The use of these particles in biopolymers matrices such as polysaccharides will be then reviewed as an innovative strategy aiming at production of eco-friendly sorbents for magnetic separation.

MAPLE (matrix-assisted pulsed laser evaporation) technique revealed a significant relevance in the deposition of bioactive nanostructures on different surfaces for the prevention and/or treatment of microbial infections associated with medical devices. Recent research progress highlights the development of two new directions for biomedical applications of magnetite nanoparticles: the antimicrobial therapy and microbial virulence and biofilm modulation. The aim of this chapter is to highlight the usefulness of functionalized magnetite nanoparticles as efficient anti-infective agents. In this respect, different type of nanocomposites based on hydrophilic/hydrophobic polymers and iron oxide nanostructures combined with natural and synthetic therapeutic agents are discussed. We offer a wide perspective regarding their synthesis, characterization, biocompatibility, and the ability to modulate the microbial attachment and biofilms development on different type of prosthetic devices or metal implants. All reported data demonstrate that magnetite-based bioactive coatings significantly inhibit the microbial colonization on the coated medical surfaces, features that together with their high in vivo viability recommend these type of thin coatings for the development of anti-infective surfaces for biomedical applications.

The deacetylated chitin derivative, chitosan (CS), as a linear polysaccharide having reactive side amino groups is among the favorite bio-based materials due to its nontoxicity, biodegradability, biocompatibility, antimicrobial properties mucoadhesivity among other advantages. Chitosan as a hydrophilic biopolymer exhibits a variety of physicochemical and biological properties resulting in numerous applications in fields such as pharmaceutical and biopharmaceutical, cosmetics, biomedical engineering, biotechnology, agriculture, textiles, food processing nutrition, etc. The mechanical properties and hardness of CS are frequently not enough to meet some of the biomedical applications requirements. The addition even of a very small amount of nanoparticles leads to obtain materials with improved mechanical, chemical, and antimicrobial properties targeted to particular application. The mechanical, thermal, and antibacterial properties of the nanocomposites as well as their biodegradability and applications are reviewed.

Nanotechnology is the engineering and art of developing new materials on a nanoscale. Due to its unique properties, the application of nanoparticles in various scientific fields, including environmental sciences, has increased greatly—numerous nanomaterials have been used for the treatment of wastewaters too. However, easy escaping and ecological risk associated with the nanomaterials limited the application in industrial scale. Recently, there has been considerable interest in the synthesis of nanocomposites from different chemical and biological materials—an important area of nanocomposite research because of its wide application in environmental sciences. Polypyrrole–bacterial extracellular polysaccharides (PPy–EPS) and polyaniline–bacterial extracellular polysaccharides (Pn–EPS) are nanocomposites with chemical and biological polymers and are good adsorbents for the removal of reactive dyes and detoxification of Cr(VI) from wastewaters. This chapter compiles the application of PPy–EPS and Pn–EPS nanocomposites in wastewater treatment.

Bacterial cellulose (BC), an environmental friendly polymeric material, has recently received immense attention in the human society. Herein, we have focused on the biosynthesis, chemical structure, and physiological behavior of BC along with synthetic routes and medical applications of its nanocomposites. The structure of BC consists of nanofibrils made up of (1 → 4) β-glycosidic linked glucose units interconnected through intra- and intermolecular hydrogen bonds. The interconnected 3D network structure of BC nanofibers with a high degree of nanoporosity makes BC an ideal candidate for the incorporation of nanomaterials to form reinforced composites. BC nanocomposites have been synthesized through a number of routes that have not only improved the existing properties of BC, but also enhanced it with novel features. Among nanomaterials, metal, metal oxides, and organic nanomaterials have been effectively used to engender antimicrobial, biocompatible, conductive, and magnetic properties in BC. BC nanocomposites have been successfully employed in the medical field and have shown a high clinical value for wound healing and skin tissue repair. Recent interest has been focused on designing ideal biomedical devices like artificial skin and artificial blood vessels from BC. This study will provide an extensive background about the primary features of BC and discuss the synthetic routes and chemical feasibility of BC nanocomposites along with their current and future application in the medical field.

Chitin, the second most abundant polymer in nature, is a renewable, nontoxic, biodegradable, and antibacterial polysaccharide. This semicrystalline biopolymer exhibits hierarchical structure from nano to micro-scale and is responsible for interesting living tissue properties. Recently, the scientific interest in chitin nanofibrils for applications in biomedical and tissue engineering fields has increased due to their particular capabilities such as matrix reinforcements, bioactivity and morphology similar to natural tissues. This chapter is focused on composite materials reinforced with chitin nanofibrils and their biomedical applications.

Grafting or deposition is a powerful tool to modify the cellulose/textile surfaces permanently with precisely controlled structure in nanometer to micrometre scale, which leads to multifunctional applications. The properties that can be imparted through functionalization include superhydrophobicity, superoleopholicity, shape memory effect, high conductivity, drug storage/delivery, flame retardant, heat storage/release, and UV protection. Through this functionalization new applications for textile can be achieved such as waterproof textiles, textile actuators, fire resistive textiles, UV-protective materials, Band-Aids, transdermal batches, medical textiles, supercapacitor electrodes, separator of oil–water mixture, wearable textile electronics, conductive textiles, self-protection cloths. This chapter summarises recent publications about modifying the cellulose surfaces with biopolymers along with nanoparticles and their composites used for superhydrophobicity, oil–water separation, conducting fabrics and drug delivery devices leading to smart bandages. The main objective is to clarify the true significance of functionalization for each application. Thus, another important purpose of this chapter is to establish general guidelines for functionalization and propose future direction for cheaper devices that can elevate the textile industries.

This chapter reviews an actual relevant literature about the most important methods used in the processing of chitosan nanocomposites, which are based on most extensively used biodegradable polymer matrices. A particular attention has been focused on the biodegradable polymer chitosan because of their widespread use in the bionanocomposite films field. Thus, the processing procedures and the results obtained of various applications from chitosan nanocomposite films have been compiled. The current research trends in chitosan-based material films for applications, including biodegradable composites and the use of chitosan are presented. This chapter will increase the interest of researchers in chitosan-based chitosan nanocomposites and the development of new ideas in this field.

Nanocomposites are the most important field of research nowadays. Metal nanoparticles have attracted continuous interest owing to their unusual properties and potential uses in electronics, optics, magnetics, catalysts, and sensors. Green synthesis (for noble metals, such as, gold, silver, platinum, palladium, etc.) and characterization of nanoparticles have emerged as a significant field of nanotechnology. As a well-known noble metal, gold is widely investigated due to its specific impact in the fields of biotechnology and bioscience. Gold nanoparticles (GNP) being the most stable metal nanoparticles have the advantages of (a) easy synthesis, (b) colloidal stability, and (c) ability to be easily conjugated with biological molecules. Gold nanoparticles also present fascinating aspects such as the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. A large number of polymer molecules were selected to decorate the surface of gold nanoparticles in physical or chemical ways for different purposes. Gold nanoparticle-reinforced nanocomposites were prepared using different polymer matrices for different types of applications such as catalytic applications, optoelectronic and magneto-optic applications, biological, medicinal applications, etc.

Silica nanoparticles, as a petroleum-free eco-friendly material, are being used in the rubber industry instead of carbon blacks. Silica nanoparticles are found to show nucleating ability for the crystallization of butadiene rubber. Furthermore, they show migration behavior from styrene-butadiene rubber to butadiene rubber by Brownian motion, indicating that the interfacial tension with butadiene rubber is lower than that with styrene-butadiene rubber.