Physics and Chemistry of Sol-Gel Nanocomposites Formation

Abstract

This method called sol-gel or dip-and spin-on-glass process, spin-spray-coating, sol -gel glasses, which was widely used in the second half of the twentieth century [1] 1 is one of the most universal condensation ways of production of nanoparticles stabilized by inorganic oxide or polymeric matrices. A special interest is attracted to materials obtained by combination of sol-gel chemistry and aerosol or spray processes, and combination of sol-gel synthesis with intercalation. This also includes combinations of sol-gel processes with different types of thermolysis, and approaches met in nature in biomineralization processes, etc., which are new aspects of integrative chemistry approach. Traditional sol-gel concept is based on hydrolysis and condensation of metal alkoxides and many metalloids including different ways of their modification [2,3]. Main reactions proceed at relatively low temperatures with usage of prepared in advance or synthesized in parallel polymers, and are convenient techniques for preparation of organic-inorganic nanocomposites compared with commercial silicate-intercalation technique. Sizes of formed nanoparticles in a composite can be reduced to 10 nm by choice of relative conditions. Polymer-inorganic materials have high mechanical strength and thermal stability in combination with optimal heat transport properties. They are widely used in practice due to unique physical and chemical properties: incorporation of nanometric inorganic component into polymeric matrix improves mechanical properties of material [4][5][6][7], permeability of polymers [8]. Light-sensitive materials are used in optic and electronic industry, printed-circuit boards, photoconductive cells, as key elements in solid coatings, packing materials, as cover materials they have good transparency [9][10][11]. For example, sol-gel method was used to produce various polymer/TiO 2 composites with high refractive index [12]. Such type of composites are used for chromatographic carriers, membrane materials, these are the main class of plastics for different applications, including airspace. Controlled properties of the surface of these colloid 1 We refer here to the recent review devoted to celebration of 40th anniversary of innovation researches in polymer-inorganic ceramics produced by sol-gel technique [1].