Nanofibers nanocomposites with

PMMA nanofiber nanocomposite with 20 wt.% Si02 nanoparticles, deformed [13, 17] ... 

Dagnon, K. L., Shanmuganathan, K., Weder, C., and Rowan, S. J. (2012]. Water-tri ered modulus changes of cellulose nanofiber nanocomposites with hydrophobic polymer matrices. Macromolecules, 45,4707-4715. 

The above polyolefin copolymers have also been used to prepare conventional composites and nanocomposites. However, similar to the case of polymer blends, not too many studies have been reported thus far. Recently, Kelarakis et al. (49) have mixed 10 wt% of surface-modified carbon nanofiber (MCNF) with propylene-ethylene random copolymer (propylene 84.3%). The MCNF acted as a nucleating agent for crystallization of the a-form of PP in the matrix. During deformation at room temperature, strain-induced crystallization took place, while the transformation from the 7-phase to a-phase also occurred for both unfilled and 10 wt% MCNF-filled samples. The tensile strength of the filled material was consistently higher than that of pure copolymer. These results are illustrated in Fig. 8.27. 

Figure 7.17 SEM images of nanocomposites with hierarchial nanostructures prepared by electrospinning followed by calcination (a) V20s-Ta205 nanorods on Ti02 nanofibers, and (b) V2O5 nanorods on Si02 nanofibers. (Reprinted with permission from R. Ostermann et al. Nano Lett. 2006, 6, 1297. Copyright (2006) American Chemical Society.)...

In this Chapter, we report on some examples of nanocomposites with CNTs, highlighting a meshwork of interactions between the mechanical, electrical and optical properties of CNTs and the interface with the polymer matrix. CNTs are considered ideal materials for reinforcing fibers due to their exceptional mechanical properties. Functionalization of CNTs seems to be the most effective way to incorporate these nanofibers into the polymer matrix. It is generally accepted that the fabrication of high-performance nanotube-polymer composite depends on the efficient load transfer from the host matrix to the tubes. If the percentage of nano-reinforcements is very low or if it is well-dispersed, there are more strong interfaces that slow down the progress of a crack. ... 

Fan J, Shi Z, Tian M, Yin J. Graphene-aramid nanofiber nanocomposite paper with high mechanical and electrical performance. RSC Adv 2013 3(39) 17664. 

The electrical conductivity, environmental stability, and surface properties of pristine polyanihne can be improved by synthesizing nanocomposite with large surface area materials such as carbon nanofibers [30]. Polyaniline/carbon nanofiber nanocomposite can be prepared by one-step vapor deposition polymerization [31]. In vapor deposition polymerization, a reactor consisting of two connecting flasks are used. In one chamber, the carbon nanofibers soaked in initiator are taken and the other chamber is equipped with a seahng apparatus. Then vacuum is appHed inside the chamber followed by the addition of liquid aniline monomer to the second chamber is carried out. The chamber is heated at low temperature in order to vaporize the anihne monomer. This process can continue... 

Non-destructive surface-functionalization of carbon nanofibers can be achieved by using poly(3,4-ethylenedioxythiophene) (PEDOT) since PEDOT is an electron donor and carbon nanofiber is an electron acceptor [40]. PEDOT/carbon nanofiber nanocomposites can be prepared by chemical polymerization process. This includes an initial adsorption of EDOT monomers on the carbon nanofibers, which is followed by the polymerization process. The adsorption of monomers on the fiber surface occurs due to the electrostatic n-n interaction. PEDOT poly(styrenesulfonate) (PEDOT PSS)/carbon nanofiber bilayer system is used particularly for electrode applications [41]. Such bilayer systems can be easily prepared with dip-coating technique.The advantage of dip-coating is that only a small amount of polymer will be adsorbed on the carbon nanofiber surface and hence nanometer thick coating is achievable. The surface area of electroactive materials can be enhanced in such bilayer systems prepared with carbon nanofibers. 

Fig. 21.10 Foldable transparent nanocomposites reinforced with bacterial cellulose nanofibers. Reproduced with permission from Nogi and Yano (2008). Copyright 2008 Wiley-VCH Verlag GmbH Co. KGaA, Weinheim...

Recently, considerable attention has been focused on the blends of biocompatible and biodegradable polymers in view of their potential environmental and biomedical applications. Song et al. [127] fabricated polylactide (PLA) nanofibers and the formation of nanocomposites with Ti02 via solution blending. The results... 

Cellulose nanofibers (CNFs) [87, 88] and nanowhiskers (CNWs) [89] derived from renewable biomass have attracted much interest as alternatives to microsized and glass-fiber reinforcements in composite materials. Jonoobi et al. [87] developed CNF-reinforced polylactic acid (PLA) by twin-screw exfrusion. Obtained PLA/CNF nanocomposites with 5 wt% CNF showed improved tensile modulus and strength. Ljungberg et al. [89] prepared nanocomposite films of isotactic-PP reinforced with cellulose whiskers, which were highly dispersed in the PP matrix with a surfactant. The surfactant-modified whiskers acted as nucleating agents for isotactic-PP and the obtained nanocomposite displayed an increased tensile strength and strain at break as compared to the neat isotactic-PP. 

Carbon Nanotube and Carbon Nanofiber Nanocomposites. The discovery of single-wall carbon nanotubes (SWNT) has renewed focus on composites with SWNT, multiwalled carbon nanotube (MWNT) and carbon nanofiber (CNF) reinforcements, together referred to as ID Nanocarbon composites (39). These constituents offer promise for new lightweight materials with incredible mechanical, electrical, and thermal properties. ID Nanocarbon materials are envisioned as multifunctional materials, eg single materials used for structures as well as electrical and/or thermal conductors. One example is electronics in a space satellite that need to be lightweight and mechanically supported, have the excess heat dissipated, and be protected from electromagnetic interference (EMI). Other examples are structures that are also batteries and structures that store hydrogen for fuel cells. 

He L X and Tjong S C (2010) Effect of temperature on electrical conduction behavior of polyvinyl-idene fluoride nanocomposites with carbon nanotubes and nanofibers, Curr Nanosci 6 520-524. Bhattacharyya A R, Sreekumar T V, Liu T, Kumar S, Ericson L M, Hauge H and Smalley R E (2003) Crystallization and orientation in polypropylene/single wall carbon nanotube composite. Polymer 44 2373-2377. 

Shimazaki Y, Ho jo F and Takezawa Y (2008) Preparation and characterization of thermoconductive polymer nanocomposite with branched alumina nanofibers, Appl Phys Lett 92 133309. 

Recent developments in polymer nanotechnology include the exfoliated clay nanocomposites, CNTs, carbon nanofibers, exfoliated graphite, nanocrystalline metals, and a host of other filler modified composite materials. Polymer matrix-based nanocomposites with exfoliated clay are discussed in this section. Performance... 

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