Organic-Inorganic Hybrid Materials and Nanocomposites

In this chapter, attention will be focused on hybrid materials involving polymeric species. However, it should be noted that a wide variety of composites are currently under research—for instance, NiO plus yttrium-stabilized zirconia (Lee et al., 2001) 

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L. Chazeau, C. Gauthier, G. Vigier and J.-Y Cavaille, "Relationships between microstructural aspects and mechanical properties in polymer based nanocomposites", in H.S. Nalwa, ed., Handbook of Organic-Inorganic Hybrid Materials and Nanocomposites, American Scientific Publishers, 2003. 

Zhang M Q, Rong M Z and Friedrich K (2003) Processing and properties of non-layered nanoparticle reinforced thermoplastic composites, in Handbook of Organic-Inorganic Hybrid Materials and Nanocomposites, vol. 2 (Ed. Nalwa H S), American Science Publishers, CaUfornia, pp. 113-150. 

Thus the sol-gel methodology is an alternative to classical thermodynamic routes for the synthesis of solids. It is also evident that the preparation of the solids through Chimie Douce bridges molecular chemistry and solid state chemistry. This chapter will be focused on material prepared by the sol-gel process, where an organic part is associated with a silica or siloxane Si—O—Si network. Two types of organic-inorganic hybrid materials can be prepared by the sol-gel process and are completely different the nanocomposites and the nanostructured hybrid materials6-9. 

Intercalation of organic molecules into layered host lattice produces a variety of organic-inorganic hybrid materials. The solvothermal method provides a reaction system that allows application of high temperatures and therefore is a powerful technique for preparation of intercalation compounds. Exfoliation of layers may occur because of applied high temperatures. For example, exfoliated poly-ethylene/montmoriUonite nanocomposites were reported to be prepared by solvothermal reaction of organophilic montmorillonite with polyethylene in toluene at 170°C for 2... 

Pyun, J., and K. Matyjaszewski. 2001. Synthesis of nanocomposite organic/inorganic hybrid materials using controlled/ living radical polymerization. Chemistry of Materials 13(10) 3436-3448. 

Recentiy, a new class of organic-inorganic hybrid materials based on the ultra incorporation of nano-sized fillers (nanofillers) into a polymer matrix has been investigated. Nanotechnology is the aptitude to work on a scale of about 1-100 nm in order to understand, create, characterize and use material structure, devices, and system with unique properties derived from their base on the nanostructures. Nanocomposites could exhibit exclusive modifications in their properties, compared with conventional composites in terms of physical properties, including gas barrier, flammability resistance, thermal and environmental stability, solvent uptake, and rate of biodegradability of biodegradable (Chivrac et al. 2009). 

The organic-inorganic hybrid materials have shown significant increases in properties compared to the conventional composites or neat polymers. The degree of dispersion of nanofiUers in a polymer matrix and the processing method play a key role on the final properties of the materials. Key objectives of researches are to design nanocomposites with enhanced properties at low filler contents. Different modified clays have been used in view of these objectives [31,52], There are reports on the use of ammonium-treated layered silicates [52,53], whereas the use of thermostable ILs such as pyridinium, imidazolium, or phosphonium is poorly reported. However, their combinations with poly(styrene) (PS) [54], PE [55], PP [56], poly(vinylidene fluoride) (PVDF) [57], and PET matrices [58] have been reported in the literature. 

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