Review of Nanocellulose Polymer Composite Characteristics and Challenges

The nanosize cellulose has emerged in the last two decades as an efficient strategy to improve the structural and functional properties of polymer composite. This review focuses to explore the unique mechanical–thermal properties of cellulose-based nanocomposites particularly on the various reinforcing mechanisms of nanocellulose. The promising reinforcing capabilities of nanocellulose mainly lie in their intrinsic chemical natures, aspect ratio, and degree of crystallinity. In this article, the potential factors deteriorating the aspect ratio and crystallinity have been systematically reviewed. Some relevant suggestions/solutions were also widely exploited toward tailoring the generating problems.     

Polymer nanocomposites from modified clays: Recent advances and challenges

Since the end of the last century, the discovery of polymer nanocomposites and their ever-expanding use in various applications has been the result of continuous developments in polymer science and nanotechnology. In that regard, progress in developments on the use of modified natural and synthetic clays for designing polymer nanocomposites is presented herein. The modified clays used in composite preparation include natural clays such as montmorrilonite, hectorite, sepiolite, laponite, saponite, rectorite, bentonite, vermiculite, biedellite, kaolinite, and chlorite, as well as synthetic clays including various layered double hydroxides, synthetic montmorrilonite, hectorite, etc. The preparation, structure and properties of polymer nanocomposites using the modified clays are discussed. Even at a low loading, these composites are endowed with remarkably enhanced mechanical, thermal, dynamic mechanical, adhesion and barrier properties, flame retardancy, etc. The properties of the nanocomposites depend significantly on the chemistry of polymer matrices, nature of clays, their modification and the preparation methods. The uniform dispersion of clays in polymer matrices is a general prerequisite for achieving improved mechanical and physical characteristics. Various theories and models used to design polymer/clay nanocomposites have also been highlighted. A synopsis of the applications of these advanced, high-performance polymer nanocomposites is presented, pointing out gaps to motivate potential research in this field.     

A Review on Polymeric Nanocomposites of Nanodiamond,Carbon Nanotube,and Nanobifiller: Structure,Preparation and Properties

In this review, an overview of various types of nanofillers is presented with special emphasis on structure, synthesis and properties of carbon nanotube, nanodiamond, and nanobifiller of carbon nanotube/nanodiamond, carbon nanotube/graphene oxide and carbon nanotube/graphene. In addition, polymer/carbon nanotube, polymer/nanodiamond, and polymer/nanobifiller composites have been discussed. The efficacy of different fabrication techniques for nanocomposites (solution casting, in-situ, and melt blending method) and their properties were also discussed in detail. Finally, we have summarized the challenges and future prospects of polymer nanocomposites reinforced with carbon nanofillers hoping to facilitate progress in the emerging area of nanobifiller technology.     

纳米纤维素及其聚合物纳米复合材料的研究进展

纳米纤维素（nanocellulose,NC）是一种具有优异力学性能、质轻、高比表面积、可再生、可生物降解等特性的新型纳米材料,纳米纤维素与聚合物结合得到的复合材料被视为新一代生物质基纳米复合材料。文章首先概述了微纤化纤维素（MFC）、纳米纤维素晶体（NCC）和细菌纳米纤维素（BC）3种主要纳米纤维素的特性及其主要的制备方法,并对其制备过程中存在的问题进行分析。其次,文章简述了纳米纤维素在亲水性聚合物（淀粉、聚乙烯醇、水性聚氨酯等）和非亲水性聚合物（聚乳酸、聚己内酯、聚羟基烷酸酯和环氧树脂等）纳米复合材料方面的研究进展。最后,指出纳米纤维素在绿色工业化生产过程中还需解决生产成本、分离技术、能耗和环境污染等问题。此外,提高纳米纤维素与聚合物之间的界面相容性,开发以纳米纤维素为主体成分的新型纳米复合材料是今后发展的一个重要方向。     

Nanocellulose-Polymer Composites for Applications in Food Packaging: Current Status,Future Prospects and Challenges

Nanocellulose has potential applications across the several industrial sectors and addresses a lot of issues related to environmental concern. As biodegradable filler in composite manufacturing, coating, and self-standing thin films, it offers novel and promising properties. Very few available reviews report on nanocellulose-impregnated composite materials for food packaging. Nanocellulose reinforcement is found to be promising for mechanical and barrier properties of composite for biopolymer and synthetic polymer. In this paper, we provide a thorough review of recent advances of nanocellulose synthesis and its application as a filler material for production of nanocomposites to be used for food packaging.     

Thermal properties of nanocellulose-reinforced composites: A review

Nanocellulose has received increasing attention in science and industry in recent years as a nanoscale material for the reinforcement of polymer matrix composites due to its superior mechanical properties, renewability, and biodegradability. New nanocellulose sources, modifications, and treatments are under development to reduce the high energy required during production and to create a more suitable industrial-scale production process. Thus, this paper reviews plant-based nanocellulose composites and their properties, with a focus on their thermal-related characteristics. The purpose of this review is to establish for readers the impact of the incorporation of nanocellulose on the thermal and dynamic mechanical properties of nanocellulose composites. Understanding of the thermal properties is important for researchers to assess the suitability of the nanocomposites for a variety of applications in response to new and evolving societal requirements. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48544.     

Recent developments in nanocellulose-based biodegradable polymers,thermoplastic polymers,and porous nanocomposites

Nanocellulose has generated a great deal of interest as a source of nanometer-sized reinforcement, because of its good mechanical properties. In the last few years, nanocellulose has also attracted much attention due to environmental concerns. This review presents an overview of recent developments in this area, including the production, characterization, properties, and range of applications of nanocellulose-based biodegradable polymers, thermoplastic polymers, and porous nanocomposites. After explaining the unique properties of nanocellulose and its various preparation techniques, an orderly introduction of various nanocellulose-reinforced biodegradable polymers such as starch, proteins, alginate, chitosan, and gelatin is provided. Subsequently, the effects of nanocellulose on the properties of thermoplastic polymers such as polyamides, polysulfone, polypropyrol, and polyacronitril are reported. The paper concludes with a presentation of new finding and cutting-edge studies on nanocellulose foam and aerogel composites. Three different types of aerogels, i.e., pristine nanocellulose-based aerogels, modified nanocellulose-based aerogels, and nanocellulose-based templates for aerogels, are discussed, as well as their preparation techniques and properties. In the case of foam composites, the research focus has been on two major preparation techniques, i.e., solvent-mixing/foaming and melt-mixing foaming, their respective challenges, and the properties of the final composites. In some cases, a comparison study between cellulose nanocrystals and cellulose nanofiber-reinforced biodegradable polymers, thermoplastics, and porous nanocomposites was carried out. Considering the vast amount of research on nanocellulose-based composites, special emphasis on such composites isprovided at the end of the review.     

One-dimensional conducting polymer nanocomposites: Synthesis, properties and applications

Intrinsically conducting polymers have been studied extensively due to their intriguing electronic and redox properties and numerous potential applications in many fields since their discovery in 1970s. To improve and extend their functions, the fabrication of multi-functionalized conducting polymer nanocomposites has attracted a great deal of attention because of the emergence of nanotechnology. This article presents an overview of the synthesis of one-dimensional (1D) conducting polymer nanocomposites and their properties and applications. Nanocomposites consist of conducting polymers and one or more components, which can be carbon nanotubes, metals, oxide nanomaterials, chalcogenides, insulating or conducting polymers, biological materials, metal phthalocyanines and porphyrins, etc. The properties of 1D conducting polymer nanocomposites will be widely discussed. Special attention is paid to the difference in the properties between 1D conducting polymer nanocomposites and bulk conducting polymers. Applications of 1D conducting polymer nanocomposites described include electronic nanodevices, chemical and biological sensors, catalysis and electrocatalysis, energy, microwave absorption and electromagnetic interference (EMI) shielding, electrorheological (ER) fluids, and biomedicine. The advantages of 1D conducting polymer nanocomposites over the parent conducting polymers are highlighted. Combined with the intrinsic properties and synergistic effect of each component, it is anticipated that 1D conducting polymer nanocomposites will play an important role in various fields of nanotechnology.     

Tensile and morphological properties of nanocrystalline cellulose and nanofibrillated cellulose reinforced PLA bionanocomposites: A review

In recent years, bionanocomposites have received growing attention in science and industry due to their renewability, biodegradability and superior mechanical properties. Nanocellulose is another promising material that use as a reinforcement filler for bionanocomposite materials due to its lightweight, high surface area, high mechanical strength, high aspect ratio and low density. Different nanocellulose loading, sources, surface modification/functionalization and properties of nanocellulose are important in the production of bionanocomposites. In general, nanocellulose reinforced PLA bionanocomposite offers enhancement in tensile strength and elastic modulus. However, only minimal nanocellulose loadings are required for optimal results due to the incompatibility between the hydrophilic nanocellulose and hydrophobic PLA. This paper reviews the sources of nanocellulose and the properties of nanocellulose with a focus on the tensile and morphological properties of PLA bionanocomposites. Applications of nanocellulose in various industries are discussed in this article. This review article provides some important information. First, this study reviewed the application of nanostructured cellulose in biodegradable polymers. There are two types of nanostructured cellulose: nanocrystalline cellulose (NCC) and nanofibrillated cellulose (NFC). Second, the status on articles published on nanocellulose and PLA/nanocellulose over the past 10 years is reported. Third, the authors of this paper implemented a holistic and critical review to provide a comprehensive understanding of the different properties between NCC and NFC, the application of nanocellulose in bionanocomposites, as well as the properties of PLA and PLA bionanocomposites. Moreover, the influence of NCC and NFC on the tensile and morphological properties of bionanocomposites is covered in this article.     

Recent advance in research on halloysite nanotubes-polymer nanocomposite

Halloysite nanotubes (HNTs) are novel 1D natural nanomaterials with predominantly hollow tubular nanostructures and high aspect ratios. Due to their high mechanical strength, thermal stability, biocompatibility, and abundance, HNTs have a number of exciting potential applications in polymer nanocomposites. In this article, we review the recent progress toward the development of HNTs-polymer nanocomposites, while paying particular attention to interfacial interactions of the nanocomposites. The characteristics of the HNTs relative to the formation of the polymer nanocomposites are summarized first. The covalent or non-covalent functionalization methods for HNTs and various fabrication approaches for HNTs-polymer nanocomposites are introduced afterward. Polymer nanocomposites reinforced with HNTs possess highly increased tensile and flexural strength, elastic moduli, and improved toughness. HNTs-polymer nanocomposites also exhibit elevated thermal resistance, flame retardance and unique crystallization behavior. Due to the tubular microstructure and the biocompatibility of HNTs, HNTs-polymer nanocomposites have demonstrated good drug encapsulation and sustained release abilities, gaining them extensive use as tissue engineering scaffolds and drug carriers. Finally, we summarize the characteristics of HNTs-polymer nanocomposites and predict for the development of the potential applications in high-performance composites for aircraft/automobile industries, environmental protection, and biomaterials.     

Research updates on graphene oxide‐based polymeric nanocomposites

Graphene oxide (GO) is a carbon‐based material, which is one atom thick sheet of graphite. The nanofillers have exceptional stiffness and strength owing to the presence of two‐dimensional graphene backbone. Especially owing to this reason, nanocomposites have been developed using GO for several applications. This review article explores the synthesis of GO from flake graphite. Main emphasis has been afforded on the preparation and characterization of GO nanocomposites, utilizing various industrial polymers for wide application in aerospace, biomedical, military, supercapacitors, electrical, sensor, and so on. Morphological characterization exploring the interaction and extent of dispersion of GO nanosheets in the polymer matrices is extensively accounted. From the reports, it is clear that exfoliation and strong interaction of GO tremendously improved the physical, mechanical, thermal, electrochemical, biocompatibility, and tribological properties of the added polymer. POLYM. COMPOS., 35:2297–2310, 2014. © 2014 Society of Plastics Engineers     

Polydimethylsiloxane-based nanocomposite: present research scenario and emergent future trends

ABSTRACT

To assess the potential value of polydimethylsiloxane (PDMS), an essential silicone polymer, it is important to determine the effective integration of nanoparticles in nanocomposites. This review basically outlines various facets of reinforced PDMS materials focusing foremost characteristics, processing, and methodological applications. The main sections are dedicated to nanocomposite categories as PDMS/nanodiamond, PDMS/graphene, PDMS/carbon nanotube, PDMS/carbon black, PDMS/quantum dot, and PDMS/inorganic nanoparticle. Moreover, significant applications of PDMS-based nanocomposites in coatings, membranes, foams, and sensors are debated. High-performance PDMS nanocomposites reveal fine electrical/thermal conductivity, robustness, thermal stability, anti-corrosion, permeability, compressibility, and superhydrophobicity/oleophilicity. Toward ending, challenges and future potential of PDMS-based nanocomposite have been conversed.     

Eco-friendly electronics,based on nanocomposites of biopolyester reinforced with carbon nanotubes: a review

ABSTRACT

Fabrication of electronic materials from nanocomposite of biopolyesters reinforced with carbon nanotubes can be regarded as the effective alternative for conventional nanocomposites consisting of non-biodegradable polymers. Commercial availability of biopolyester-based nanocomposites is limited because of their high cost compared to other polymers, but the factor of their compostable nature is worthless for environmental protection. Such nanocomposites have potential applications in biodegradable sensors, EMI materials, etc. In this review, the current progress of biopolyester/CNTs nanocomposites in the field of biodegradable electronics is reviewed and also the impact of CNTs dispersion on electrical, thermal and mechanical properties of eco composites is stipulated.     

Graphene-based polymer nanocomposites

Graphene-based materials are single- or few-layer platelets that can be produced in bulk quantities by chemical methods. Herein, we present a survey of the literature on polymer nanocomposites with graphene-based fillers including recent work using graphite nanoplatelet fillers. A variety of routes used to produce graphene-based materials are reviewed, along with methods for dispersing these materials in various polymer matrices. We also review the rheological, electrical, mechanical, thermal, and barrier properties of these composites, and how each of these composite properties is dependent upon the intrinsic properties of graphene-based materials and their state of dispersion in the matrix. An overview of potential applications for these composites and current challenges in the field are provided for perspective and to potentially guide future progress on the development of these promising materials.     

Compatibilizing Effect of Halloysite Nanotubes on Polyetherimide/Silicone Rubber Blend Based Nanocomposites

The present study deals with the preparation of nanocomposites comprising of polyetherimide (PEI) and silicone rubber reinforced with both unmodified and modified halloysite nanotubes (HNTs) by melt blending process with the aid of co-rotating twin screws extruder. The developed nanocomposites have been characterized by various sophisticated analytical instrument viz. TGA, DMA, SEM,TEM, FTIR and UTM. There is remarkable enhancement in various properties of the developed nanocomposites due to incorporation of modified HNTs. This can be attributed to fairly good dispersion of the HNTs in the polymer matrix resulting in reductions of filler-filler interaction.     

Recent development in thermoplastic/wood composites and nanocomposites: A review

Thermoplastic composites filled with wood-base fillers have gained increasing attention, because compared to virgin polymers they have many advantages of light weight, high strength and stiffness, low cost, biodegradability and renewability. These advantages let them find a large dispersal in many areas of technical applications. However, poor interfacial interaction between hydrophilic wood-base fillers and hydrophobic polymer matrices should be improved to get reasonable physical properties for their wide applications. The interfacial interaction could be improved by addition of coupling agents and chemical modifications of wood-base fillers. To improve physical properties of the thermoplastic/wood composites, further nanofillers can be incorporated. This review summarizes recent developments in thermoplastic/wood composites and deals with wood-base fillers for thermoplastics, various interface modification methods and various thermoplastic/wood composites as well as nanocomposites. This review can provide reasonable future perspectives in this research area and stimulate development of new innovative thermoplastic/wood composites as well as nanocomposites.     

聚合物/介孔分子筛复合材料研究进展

介绍了聚合物/介孔复合材料的制备方法,即原位聚合法和共混法,分析了其结构与性能特点和增强机理,综述了近年来无机介孔粒子-聚合物复合材料的应用领域。     

Polymer-based composites by electrospinning: Preparation & functionalization with nanocarbons

Electrospinning is a straightforward yet versatile technique for the preparation of polymeric nanofibers with diameters in the range of nanometers to micrometers, and has been rapidly developed in the last two decades. Nanocarbon materials, usually referring to carbon nanotubes, graphene, and fullerenes with their derivatives including quantum dots, nanofibers, and nanoribbons, have received increasing attention due to their unique structural characteristics and outstanding physico-chemical properties. Incorporation of nanocarbons in electrospun polymeric fibers has been used to increase the functionality of fibers, for example, to improve the mechanical, electrical, and thermal properties, as well as confer biofunctionality as scaffolds in tissue engineering and sensors, when the advantageous properties given by the encapsulated materials are transferred to the fibers. In this review, we provide an overview of polymer-based composites reinforced with nanocarbons via the electrospinning technique. After a brief introduction of various types of nanocarbons, we summarize the latest progress of the design and fabrication of electrospun polymeric nanofibers with nanocarbon fillers. With regard to the preparation of composites, we focus on functionalization strategies of nanocarbons and the production of random & aligned polymeric nanocomposites. Then, the physical properties such as mechanical, electrical, and thermal properties are also reviewed for electrospun nanocomposite nanofibers reinforced with nanocarbons, especially carbon nanotubes. Benefiting from the exceptional properties including superior electric conductivity, high porosities, unique mat structure, etc. the polymeric composite nanofibers have demonstrated numerous advantages and promising properties in the fields of tissue engineering and sensors. In the application section, we will give state-of-the-art examples to demonstrate the advantages of electrospun polymer-based nanocomposites. Finally, the conclusion and challenge of the polymer-based nanocomposites are also presented. We believe the efforts made in this review would promote the understanding of the methods of preparation and unique physical and chemical properties of nanocarbon reinforced polymer-based nanocomposites.     

Exploitation of Carbon Nanotubes in High Performance Polyvinylidene Fluoride Matrix Composite: A Review

Among nanocarbon fillers, carbon nanotubes are considered to be an ideal reinforcement due to their miniscule size, and excellent electrical, thermal, and mechanical properties. However, carbon nanotubes can be utilized in polymer nanocomposites only if they are homogenously dispersed into polymer matrices. The multiwalled carbon nanotube has been concentrated as a reinforcement for an important type of thermoplastic polyvinylidene fluoride. This review initially focuses on carbon nanotubes modification both by mechanical methods and chemical functionalization to improve their dispersion. Moreover, the processing methods for polyvinylidene fluoride/carbon nanotubes nanocomposite have been discussed. Multiwalled carbon nanotubes facilitate the electrical conductivity, thermal, rheological, and mechanical properties of polyvinylidene fluoride.     

Polyaniline–Carbon Nanotube Composites: Preparation Methods,Properties, and Applications

Synthesis of polyaniline and hybrid carbon nanotube reinforced polyaniline nanocomposites by various methods has discussed in this review. Different routes used for functionalization of carbon nanotube have been reported. The electrical, mechanical, and thermal properties of polyaniline/carbon nanotube nanocomposites are also discussed. The dispersion of functionalized carbon nanotube, filler concentration, and their alignment in the interior of polyaniline matrix affect their morphology. Furthermore, article focussed upon the various morphologies of polyaniline and polyaniline/carbon nanotube nanocomposites obtained with different methods along with electrical conductivity. Possible applications of polyaniline/carbon nanotube nanocomposites in the areas of actuators, sensors, electromagnetic interference shielding have also discussed.