| Silicon dioxide is not only an important kind of semiconducting material, but also used to be the filler of plastics, rubber, coating and adhesive because of its good properties of heat-resistant ,climate-resistant, and chemical stability .Therefore, preparation of SiO2 nanoparticles is very valuable for application. Now there are many preparing methods introduced in literature, but there are some technical problems in the preparation of SiO2 nanoparticles /emulsion coating and adhesive. For instance, the nano SiO2 was prepared in organic solvent by sol-gel method which could not be dispersed into emulsion directly; If it was dispersed in solid state, the stable dispersion in nana size was a difficult problem because nano SiO2 are strong hydrophilic, very sensitive with pH value of medium and have a tendency to reunite.In this paper silicon sol was prepared by traditional silicon and ion exchanging methods, with the base of "formation in situ" and "desperation in situ". The surface of SiO2 particle was modified in situ by organic silicon compound, lipotropic SiO2 namoparticle dispersed in aqueous solution was systhesized. The effects of various factors on nano SiO2 nanoparticle size size distribution yield and dispersing stability were studied systematically. The optimum raw material formula and technological conditions were determined. These methods not only have the advantages of simple and convenient, price of cheap, but also solve efficiently distribution stability of nano SiO2 in water phase . The prospect of application will be extensive.With lipotropic surface modified SiO2 nanoparlicles as nuclei above mentioned, acrylic esters as comonomer , nano SiO2 /acrylic ester polymer composite emulsion with normal nucleolus/shell structure was synthesized by the processing of seed emulsion polymerization, the optimum formula of feed stock and processing conditions were determined by analysis of theory as well as a lot of experimental researches. The factors on influencing emulsionpolymerization as well as the structure and shape of emulsion particles were studied.The emulsion coating was prepared with the mentioned emulsion as base. As compared with the adding nano SiO2-polyacrylic ester emulsion coating and the common polyacrylic ester emulsion coating, this kind of coating provided with good weather fastness, water proof, alkali resistivity, washing fastness, anticontamination, enhancement and good tenacity et. al. These good properties stem from the features of nanoparticles and score/shell structure in base, as well as good characters of organic siloxanes . This emulsion would be extensively applied in the fields of rubber, paper and adhesive et. al.
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