Development of Biopolymer Nanocomposites Based on Polysaccharides Obtained from Red Algae Chondracanthus chamissoi Reinforced with Chitin Whiskers and Montmorillonite

Polysaccharides from various species of algae have many applications in the food and biomedical industry. The aim of this study was to characterize nanocomposites developed from carrageenan extracted from the red algae Chondracanthus chamissoi and reinforced with montmorillonite and chitin nanowhiskers. The nanocomposites showed improved mechanical properties compared to the biopolymeric matrix. Montmorillonite-reinforced nanocomposites displayed the most favorable properties at 5% of clay concentration; meanwhile, the chitin-nanocomposites showed an improvement in the mechanical properties correlating to the increase in chitin concentration. These results will aid in the development of more environmentally friendly materials.     

Recent Advances in Boron Nitride Based Hybrid Polymer Nanocomposites

Boron nitride (BN) is an eminent inorganic compound having many interesting characteristics such as improved oxidation resistance, mechanical strength, good thermal conductivity (TC), higher bandgap, high chemical stability, thermal stability, high hydrophobicity, and electrical insulation. The use of BN as a filler in polymers is a well-established strategy to tailor the properties of polymer composites. Recent studies depict an interesting urge to reap the synergistic effect of various nanofillers with BN in the form of hybrids. Hence the consolidation of the works on BN based hybrid fillers would definitely attract researchers so that these new filler systems could be transformed into useful polymer nanocomposites in future. This review article focuses on the synthesis and characterization of various boron nitride based hybrids in detail. Moreover, the review also throws light on different BN hybrid reinforced polymer nanocomposites (PNCs) and their thermal, electrical, electronic as well as biomedical applications in a detailed manner. Thus the review anticipates serving as a tool toward understanding the recent trends in the field of boron nitride hybrid based ternary polymer composites.     

Polymeric nanostructured materials for biomedical applications

Polymeric nanostructured materials (PNMs), which are polymeric materials in nanoscale or polymer composites containing nanomaterials, have become increasingly useful for biomedical applications. In specific, advances in polymer-related nanoscience and nanotechnology have brought a revolutionary change to produce new biomaterials with tailored properties and functionalities for targeted biomedical applications. These materials, including micelles, polymersomes, nanoparticles, nanocapsules, nanogels, nanofibers, dendrimers and nanocomposites, have been widely used in drug delivery, gene therapy, bioimage, tissue engineering and regenerative medicine. This review presents a comprehensive overview on the various types of PNMs, their fabrication methods and biomedical applications, as well as the challenges in research and development of future PNMs.     

Multifunctional Magnetic-fluorescent Nanocomposites for Biomedical Applications

Nanotechnology is a fast-growing area, involving the fabrication and use of nano-sized materials and devices. Various nanocomposite materials play a number of important roles in modern science and technology. Magnetic and fluorescent inorganic nanoparticles are of particular importance due to their broad range of potential applications. It is expected that the combination of magnetic and fluorescent properties in one nanocomposite would enable the engineering of unique multifunctional nanoscale devices, which could be manipulated using external magnetic fields. The aim of this review is to present an overview of bimodal “two-in-one” magnetic-fluorescent nanocomposite materials which combine both magnetic and fluorescent properties in one entity, in particular those with potential applications in biotechnology and nanomedicine. There is a great necessity for the development of these multifunctional nanocomposites, but there are some difficulties and challenges to overcome in their fabrication such as quenching of the fluorescent entity by the magnetic core. Fluorescent-magnetic nanocomposites include a variety of materials including silica-based, dye-functionalised magnetic nanoparticles and quantum dots-magnetic nanoparticle composites. The classification and main synthesis strategies, along with approaches for the fabrication of fluorescent-magnetic nanocomposites, are considered. The current and potential biomedical uses, including biological imaging, cell tracking, magnetic bioseparation, nanomedicine and bio- and chemo-sensoring, of magnetic-fluorescent nanocomposites are also discussed.     

PLGA-Based Composites for Various Biomedical Applications

Polymeric materials have been extensively explored in the field of nanomedicine; within them, poly lactic-co-glycolic acid (PLGA) holds a prominent position in micro- and nanotechnology due to its biocompatibility and controllable biodegradability. In this review we focus on the combination of PLGA with different inorganic nanomaterials in the form of nanocomposites to overcome the polymer’s limitations and extend its field of applications. We discuss their physicochemical properties and a variety of well-established synthesis methods for the preparation of different PLGA-based materials. Recent progress in the design and biomedical applications of PLGA-based materials are thoroughly discussed to provide a framework for future research.     

Advancements in MXene-Polymer composites for various biomedical applications

2D materials have brought about significant technological advancements in the field of biomaterials. ‘MXene’, a ceramic-based 2D nanomaterial, is comprised of transition metal carbides, nitrides, and carbonitrides having a planar structure educed from a ceramic ‘MAX’ phase by etching out ‘A’ from it, has emerged to surpass drawbacks of conventional biomaterials. In spite of their substantial properties like large surface area, biocompatibility, hydrophilicity, metallic conductivity, and size tunability, the use of MXene is restricted in biomedical applications due of its poor stability in physiological environments, lack of sustained and controlled drug release, and low biodegradability, and these limitations lead to the notion of adopting MXene/Polymer nanocomposites. The availability of functional groups on the surface of MXenes enables polymer functionalization. These polymers functionalized MXene nanocomposites exhibit high photothermal conversion efficiency, selectivity, and stimuli-responsiveness towards malignant cells, electron sensitivity, higher antibacterial properties, and the like. This review emphasizes the innovative exemplars of polymer functionalized MXene composites for the burgeoning biomedical applications, which include controlled and sustained drug delivery, antibacterial activity, photothermal cancer therapy, unambiguous biosensing, contrast-enhanced diagnostic imaging, and bone regeneration.     

Evolution from graphite to graphene elastomer composites

Elastomer composites have established a unique position among technologically important materials because of their extensive and potential applications. Considerable interest has been devoted to graphite derived elastomer composites, known as new generation materials, due to their exceptional electrical, mechanical and permeability properties. The discovery of graphene opened a promising aspect towards the synthesis of elastomer nanocomposites. A thorough investigation of the properties of various graphitic fillers, such as natural graphite flakes, expanded graphite (EG), graphite nanoplatelets (GNP) and graphene is undertaken in this review. The dependence of these fillers on the rheological, electrical (sensing), mechanical, thermal, dielectric and barrier properties of elastomer composites is discussed, giving special emphasis to particle size and mode of interactions with the matrix. A systematic evolution from microcomposites to nanocomposites is shown to give definitive evidence of the importance of graphene nanocomposites. Most preparation methods of these composites are covered, including, solution blending, latex compounding, in situ polymerization, and melt intercalation. Graphene exhibits very good dispersion in most elastomers and substantially improves the mechanical and electrical properties of the matrix compared to all other graphite derivative composites. A review of the potential applications of these composites and current challenges is provided in order to guide future progress on the development of more promising materials.     

A short review on rubber/clay nanocomposites with emphasis on mechanical properties

The invention of Nylon‐6/clay nanocomposites by the Toyota Research Group of Japan heralded a new chapter in the field of polymer composites. This article highlights the work done in the field of rubber/clay nanocomposites. The preparations of rubber/clay nanocomposites by solution blending, latex compounding, and melt intercalation are covered and a thorough discussion of the mechanical properties of the various rubber/clay nanocomposite systems is presented. Other properties such as barrier, dynamic mechanical behavior, and thermal properties are also discussed. Finally, the future trends in the rubber/clay nanocomposites are mentioned. POLYM. ENG. SCI., 47:1956–1974, 2007. © 2007 Society of Plastics Engineers     

Direct-write maskless lithography of LBL nanocomposite films and its prospects for MEMS technologies

Application of nanocomposites in MEMS, flexible electronics, and biomedical devices is likely to demonstrate new performance standards and resolve a number of difficult technical problems enabled by the unique combinations of electrical, optical, and mechanical properties. This study explores the possibility of making microscale nanocomposite patterns using the fusion of two highly versatile techniques: direct-write maskless UV patterning and layer-by-layer assembly (LBL). Together they can be applied to the production of a wide variety of nanostructured coatings with complex patterns. Single-walled carbon nanotube (SWNT) and gold nanoparticle LBL nanocomposites assembled with chitosan (CH) were made into prototypical patterns such as concentric helices and bus-line-and-stimulation-pads (BLASPs) used in flexible antennas and neuroprosthetic devices. The spatial resolution of the technique was established with the standard line grids to be at least 1 μm. Gold nanoparticle films revealed better accuracy and higher resolution in direct-write patterning than SWNT composites, possibly due to the granular rather than fibrous nature of the composites. The conductivity of the patterned composites was 6.45 × 10(-5)Ω m and 3.80 × 10(-6)Ω m at 20 °C for nanotube and nanoparticle composites, respectively; in both cases it exceeds electrical parameters of similar composites. Fundamental and technological prospects of nanocomposite MEMS devices in different areas including implantable biomedical, sensing, and optical devices are discussed.     

Electrical properties of polymer nanocomposites containing rod-like nanofillers

We present an in-depth critical review of major experimental, simulation, and theoretical work in the field of conducting polymer nanocomposites containing rod-like particles such as carbon nanotubes and metal nanowires. These are a versatile class of materials that are of interest for a wide range of applications. Commercialization of various classes of conducting polymer nanocomposites is growing, yet achieving their full technological potential will hinge on the ability to engineer composites with controllable and well-defined properties, as well as aggressive exploration of new application areas. Thus, the focus of this review is to clarify key structure–property relationships, and to discuss the major gaps and greatest opportunities in the field.     

Preparation，properties and applications of hydroxyapatite/synthetic polymer composites

随着生物医用材料的需求量日趋增大,磷灰石与人工合成高分子的复合材料成为组织修复和替代材料的研究热点。以不同单体分类,综述了磷灰石与合成的非降解高分子、可降解高分子复合材料的研究进展;对羟基磷灰石/合成高分子复合材料的制备方法、性能及其应用等方面进行研究,并对此复合材料存在的问题和发展前景进行讨论。说明从分子水平设计出具有良好力学性能、生物活性和生物相容性的医学材料,具有十分重要的意义。     

Carbon Nanomaterial–Reinforced Epoxy Composites: A Review

Conducting fillers such as graphite, carbon nanotubes, and carbon nanofibers are used as reinforcing agents for enabling the conducting behavior of epoxy resin. The present review focused on the work related to epoxy composite with reinforcement of various nanofillers. Different methods of preparation for epoxy-based conducting nanocomposites are summarized. Various characterization techniques of epoxy composites such as Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are discussed. Important properties of epoxy-based nanocomposites are explained with different applications of epoxy-based conducting polymers.     

Polymer nanotechnology: Nanocomposites

In the large field of nanotechnology, polymer matrix based nanocomposites have become a prominent area of current research and development. Exfoliated clay-based nanocomposites have dominated the polymer literature but there are a large number of other significant areas of current and emerging interest. This review will detail the technology involved with exfoliated clay-based nanocomposites and also include other important areas including barrier properties, flammability resistance, biomedical applications, electrical/electronic/optoelectronic applications and fuel cell interests. The important question of the “nano-effect” of nanoparticle or fiber inclusion relative to their larger scale counterparts is addressed relative to crystallization and glass transition behavior. Of course, other polymer (and composite)-based properties derive benefits from nanoscale filler or fiber addition and these are addressed.     

Carbon-family materials for flame retardant polymeric materials

As an abundant and attractive element, the emergence of new carbon-based materials brings revolutionary development in material science and technology. Carbon-based materials have spawned considerable interest for fabricating polymer composites/nanocomposites with greatly improved mechanical, thermal, gas barrier, conductivity, and flame retardant performance. In this review, the importance of carbon-based materials and the necessity of fire resistance for polymeric materials are initially introduced. Then, the fundamental flame retardant mechanisms and experimental analytical techniques are described to understand the relationship between structures and flame retardant properties. The main section is dedicated to the preparation and properties of multifunctional polymer composites/nanocomposites with carbon-based materials, with special emphasis on the flame retardant properties of these materials. A wide variety of carbon-based materials are discussed for use in flame retardant polymer nanocomposite, including graphite, graphene, carbon nanotubes, fullerenes as well as some new emerging carbon forms (carbon nitride, carbon aerogels, etc). Finally, a brief outlook at the developments in carbon-based materials for flame retardant polymeric composites is given by discussing the major progress, opportunities, and challenges.     

Alumina/Zirconia Micro/Nanocomposites: A New Material for Biomedical Applications With Superior Sliding Wear Resistance

In the present investigation, the sliding wear behavior is described for Al₂O₃/ZrO₂ micro/nanocomposites and monolithic alumina of similar grain size under defined conditions of a constant sliding speed and different loads (20–150 N). Nano ZrO₂ particles (1.7 vol%) were observed uniformly distributing throughout the composites, and most of them were located within the matrix alumina grains. The wear rate of the alumina and the micro/nanocomposites increased as the contact load increased and a clear transition in friction and wear behavior was observed in both materials. However, the nanocomposite wear resistance at low contact loads was one order of magnitude higher than that of the alumina. In the severe regime, no difference was observed among the materials. The low wear rate (10⁻⁷ mm³·(N·m)⁻¹) along with low pullout indicates higher wear resistance of micro/nanocomposites in the mild regime compared with monolithic alumina. Based on the morphological observation of worn surfaces by scanning electron microscope and on residual stress analysis performed by neutron diffraction, some wear mechanisms of Al₂O₃–ZrO₂ micro/nanocomposites are proposed. The high wear resistance of the nanocomposites is discussed in terms of fracture resistance properties and residual stress. Improvements in mechanical and tribological properties of these composites make them promising candidates for biomedical applications.     

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.     

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.     

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.     

Review on Nanocellulose Polymer Nanocomposites

Recently, nanocellulosic materials have been received significant research interest as potential nanofiller for the reinforcements in the polymer matrices due to its renewable in nature, readily availability, biocompatibility, inexpensive, excellent physical properties, tailorable surface properties, etc. In this review, author attempted to provide an overview of various methods for nanocellulose reinforced polymer nanocomposites fabrications, properties of nanocellulose-based nanocomposites, and their applications. The review has been emphasized for the reinforcement of nanocellulose in various polymer matrices viz. hydrophilic, hydrophobic matrices. Nanocellulose reinforced polymer nanocomposites have huge potential in diverse applications which ranges from biomedical, packaging, electronic to environmental, water treatment fields etc.     

Thermal stability of natural fibers and their polymer composites

Natural fiber-based composites are applied in many structural engineered products from civil constructions to automobile manufacturing due to the properties such as low density, high aspect ratio, biodegradability and ease to work. During the past decades such composites have been thoroughly studied for their mechanical properties and failure behavior and their properties compared with those of synthetic fiber-based composites. Other properties, such as the thermal behavior of natural fibers and composites, have also been studied because they determine the performance of their products possible. It deals with the effect of temperature on adhesive curing, effect of high temperature and fire damage during fabrication. Further, the thermal properties have equal importance in structural applications such as temperature transfer from end to end, load capacity at specific temperature, material behavior and dimensional stability at high temperature. In this respect the isothermal and non-isothermal thermogravimatric analyses are discussed and the improtance of glass transition temperature is studied during prepapration of composites to ensure their ultimate properties. Although there are several works that have been done on thermal behavior, especially thermogravimetric analysis of natural fibers and their composites, there is no review article available specially focused on natural fiber-based composites, hybrid composites, and nanocomposites. The aim of this review was to focus on the advances in the comprehension of thermogravimetric behavior of natural fibers and compare the effect of natural fibers as reinforced materials in polymer composites.