Study On Preparation And Characterization Of SiO₂/Silicone Hybrid Materials By Sol-Gel Process

With the development of science and technology, hybrid materials absorb more and more attention. Organic/inorganic hybrid material is a new type composite, in which inorganic components bind to organic components via some method. Because this kind material can show good properties of organic and inorganic components, It will be widely used in the fields of optoelectronic industry, information industry and some other science and technology. Recently, high performance hybrid material of SiO₂/organosilicone with low surface energy, heat-resistance, good chemical stability and water resistance, light transparency, etc was expected. But phase separation is often found in the process of SiO₂/organosilicone hybrid material preparation, which will effect greatly on the hybrid material's properties. The extensive applications of hybrid materials depend on improvement of morphology of the phase separation or the components of hybrid material disperse in molecular scale.SiCVorganosilicone hybrid material has been prepared via the Sol-Gel process with TEOS as inorganic precursor, MTES and DDS as organic precursors. Its properties were also researched in this paper. The effects of the catalysts, solvent and other synthesis parameters on the properties of hybrid material were detailedly investigated. Furthermore, the hybrid material coating was prepared via the Sol-Gel process mentioned above and the properties of coating were also studied.It was found that different catalysts caused different effects on the reaction process and product's morphology, during preparation of the SiO₂ sol.(1) Hydrolysis reaction of TEOS was fast in the beginning of the reaction when acidic catalyst was used. On the contrary, it was slowly carried out when basic catalyst was adopted.(2) Different morphologies of SiO₂ sol system were found via TEM when using different catalysts. It was homogeneous when acidic catalyst was used and was multiphase when basic catalyst was used. The above-mentioned conclusion could be once more confirmed through FTIR and spectrophotometer.It was proved that the prepared hybrid material was transparent and its components were dispersed in molecular scale through FTIR, TEM, DSC, spectro-photometer, solvent extraction, etc.The relationship of the performance of hybrid material coating prepared via the Sol-Gel process with the amount of TEOS was investigated, combining the results of mechanical properties, thermodynamic properties, curing performance and surface energy. The best molar ratio of TEOS to siloxane monomer was determined as 2:5. The hybrid material coating also exhibited good properties of acid-proof, salt water resistance, but had bad alkali-proof property.The effects of the molar ratios of water and ethanol to siloxane monomer, the amount of catalyst on the hybrid material sol system's viscosity and stock stability were studied. It was conducted that the suitable amount of catalyst was 0.20g and the molar ratio of both water and ethanol to siloxane monomer was 2.The big block hybrid material was prepared under non-supercritical drying through adding DCCA to hybrid material sol system or reducing solvent's surface tension, which conquered disadvantages of hybrid material prepared by Sol-Gel process.In a word, SiCVorganosilicone hybrid material coating whose components dispersed in molecular scale has been successfully prepared in this paper and this hybrid material coating exhibited good mechanical properties, low surface energy, good heat-resisting and chemical stability, high light transparency, etc, which will be found wide use in the civil and military fields.