Materials evaluated nanocomposites

However, there are few reports on chitosan/bentonite nanocomposites (Yang Chen, 2007 Zhang et al., 2009 Wan Ngah et al., 2010). The physical properties and biological response of chitosan strongly depend on the starting materials and nanocomposite preparation conditions. In the present study chitosan/day nanocomposites were prepared using two kinds of clay and different chitosan/day ratios, to evaluate how these variables affect the dispersion of clay particles into the chitosan matrix. The samples obtained were characterized by infrared spectroscopy, x-ray diffraction, and mechanical (tensile) properties. 

Recent demands for polymeric materials request them to be multifunctional and high performance. Therefore, the research and development of composite materials have become more important because single-polymeric materials can never satisfy such requests. Especially, nanocomposite materials where nanoscale fillers are incorporated with polymeric materials draw much more attention, which accelerates the development of evaluation techniques that have nanometer-scale resolution." To date, transmission electron microscopy (TEM) has been widely used for this purpose, while the technique never catches mechanical information of such materials in general. The realization of much-higher-performance materials requires the evaluation technique that enables us to investigate morphological and mechanical properties at the same time. AFM must be an appropriate candidate because it has almost comparable resolution with TEM. Furthermore, mechanical properties can be readily obtained by AFM due to the fact that the sharp probe tip attached to soft cantilever directly touches the surface of materials in question. Therefore, many of polymer researchers have started to use this novel technique." In this section, we introduce the results using the method described in Section 21.3.3 on CB-reinforced NR. 

While the variety of NPs used in catalytic and sensor applications is extensive, this chapter will primarily focus on metallic and semiconductor NPs. The term functional nanoparticle will refer to a nanoparticle that interacts with a complementary molecule and facilitate an electrochemical process, integrating supramolecular and redox function. The chapter will first concentrate on the role of exo-active surfaces and core-based materials within sensor applications. Exo-active surfaces will be evaluated based upon their types of molecular receptors, ability to incorporate multiple chemical functionalities, selectivity toward distinct analytes, versatility as nanoscale receptors, and ability to modify electrodes via nanocomposite assemblies. Core-based materials will focus on electrochemical labeling and tagging methods for biosensor applications, as well as biological processes that generate an electrochemical response at their core. Finally, this chapter will shift its focus toward the catalytic nature of NPs, discussing electrochemical reactions and enhancement in electron transfer. 

As discussed earlier, while the scale of the fillers is substantially different, nanocomposite materials concepts and technology are very similar to those of conventional composite materials. This is clearly demonstrated in the case of new thermosets for nonlinear optical (NLO) applications, " " where nanocomposite of liquid crystalline thermosets, IPNs, and simple filled thermosets are evaluated. Tripathy et al. discussed four different ways to prepare nonlinear optical polymers. (1) The polymer matrix is doped with NLO moieties in a guest/host system (2) In side-chain polymer systems, NLO polymers with active moieties are covalently bonded as pendant groups (3) In the main chain polymer, the chromo-phores are incorporated as parts of the main polymer backbone to enhance the temporal stability of the NLO properties and (4) Stability of the optical noninearity in sol-gel-based thermosets is related to... 

This volume is including information about thermal and thermooxidative degradation of polyolefine nanocomposites, modeling of catalytic complexes in the oxidation reactions, modeling the kinetics of moisture adsorption by natural and synthetic polymers, new trends, achievements and developments on the effects of beam radiation, structural behaviour of composite materials, comparative evaluation of antioxidants properties, synthesis, properties and application of polymeric composites and nanocomposites, photodegradation and light stabilization of polymers, wear resistant composite polymeric materials, some macrokinetic phenomena, transport phenomena in polymer matrix, liquid crystals, flammability of polymeric materials and new flame retardants. 

Boomi and co-workers [27] reported the synthesis of a platinum colloid and platinum-palladium colloid, pristine PANI, PANI/platinum nanocomposite and PANI/platinum-palladium nanocomposite, which were synthesised using a simple chemical method. The synthesised materials were evaluated for antibacterial activity using MIC and MBC. The results indicated that the nanocomposites exhibited improved antibacterial activity in comparison to pristine PANI and individual metal colloids. This is the first report of the chemical synthesis of a PANI/platinum-palladium nanocomposite which exhibits antibacterial activity at micromolar concentration levels. 

The objective of this work was to use rice straw pulp cellulose fiber to prepare environmental-friendly rice straw fibril and fibril aggregates (RSF) and evaluate the fibril and fibril aggregates as a novel reinforcing material to compound polypropylene (PP)/ RSF nanocomposite. The scanning electron microscopy (SEM), wide angle X-ray diffraction (WAXD), laser diameter instrument (LDl) were used to evaluate the characteristics of RSF. The RSF/PP nanocomposite was prepared by novel extrusion process. The interface compatibility and tensile properties of nanocomposite were investigated by FTIR and tensile test, respectively. 

These are fields defined throughout space in the continuum theory. Thus, the total energy of the system is an integral of these quantities over the volume of the sample dt). The FEM has been incorporated in some commercial software packages and open source codes (e.g., ABAQUS, ANSYS, Palmyra, and OOF) and widely used to evaluate the mechanical properties of polymer composites. Some attempts have recently been made to apply the FEM to nanoparticle-reinforced polymer nanocomposites. In order to capture the multiscale material behaviors, efforts are also underway to combine the multiscale models spanning from molecular to macroscopic levels [51,52]. 

Schneider OD, Weber F, Brunner TJ, Loher S, Ehrbar M, Schmidlin PR, et al. In vivo and in vitro evaluation of flexible, cottonwool-Uke nanocomposites as bone substitute material for complex defects. Acta Biomater 2009 5 1775-84. 

Armentano I, Marinucci L, Dottori M, Balloni S, Fortunati E, Pennacchi M, et al. Novel poly(L-lactide) PLLA/SWNTs nanocomposites for biomedical applications material characterization and biocompatibility evaluation. J Biomat Sci Polym Ed 2011 22 541-56. 

Epoxy-modified Mesua ferrea L. seed oil-based conventional polyurethane nanocomposites prepared by an ex situ solution technique under high mechanical shearing and ultrasonication at room temperature with different (1,2.5 and 5) wt% loadings of clay have been evaluated as biocompatible materials. The partially exfoliated nanocomposites exhibited two- and... 

The effectiveness of organoclay in NR was observed and reported by Carli et They evaluated the technical feasibility of NR nanocomposites with Cloisite 15A, a commercial organoclay to substitute conventional silica (Si02) filler. TEM analysis indicated that the OMt was homogeneously dispersed in the rubber matrix. A shift of the characteristic peaks to lower angles was observed in XRD, attributed to the intercalation of the OMt by macromolecular rubber chains. Based on the mechanical properties of the compounds they concluded that 50 phr of silica can be replaced by 4 phr of OMt with a reduction in the filler content by 12.5 times, without adversely affecting the tensile properties of the final material even after ageing. 

The new nanocomposite materials can be produced having improved physical, thermal and flammability properties with controlled durability, by having various types of nanoparticles. However, the degradation durability and toxicity of polymer-nanoparticles systems have to be evaluated for each nanoparticle with different polymers matrix under different environmental conditions for realizing the potential of nanomaterials. 

To create nanocomposites materials with specific applications the nanoparticles dispersion control into the polymer matrices still remains a critical challenge for researchers. So, the development of nanocomposite materials requires control over nanoparticle distribution in the polymer matrix. Making connections between nanoparticle dispersion, enhanced the macroscale properties and evaluated the end of life of this materials is then a crucial aspects that is only now beginning to be considered by researchers around the world. So, make these connections is essential to better development and application of the nanotechnology in the near future. 

Yoshihiko Arao received his Ph.D. (2010) at the University of Waseda (Japan) under the supervision of Hiroyuki Kawada. There he spent 4 years as Assistant Professor at the Doshisha University. He published more than 30 papers, and his h-index is 6. He became involved from manufacturing to evaluation of polymer-based composite materials. Now he is focused on the mechanical and functional properties of nanocomposites. Contact Yoshihiko.arao gmail.com... 

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