摘要：通过液相法制备棒状SiO2颗粒,研究正硅酸乙酯的浓度和聚乙烯吡咯烷酮的相对分子质量对棒状SiO2颗粒的影响,利用液相沉积法在最优化条件下制备的棒状SiO2颗粒表面均匀包覆TiO2,制备棒状SiO2-TiO2核壳结构粒子,并采用X射线衍射、透射电镜和傅里叶红外光谱等手段对棒状SiO2-TiO2核壳粒子进行表征。结果表明,随着聚乙烯吡咯烷酮相对分子质量的增大,SiO2颗粒由大头针状转变为棒状,随着正硅酸乙酯浓度的增大,棒状SiO2颗粒的长径比变大并出现类球状颗粒;棒状SiO2表面包覆的TiO2为针状,晶型为锐钛矿,包覆厚度为80 nm左右。
关键词：二氧化硅；二氧化钛；核壳粒子
Abstract：Rod-like silica particles were prepared by liquid phase method under mild conditions.Influences of the tetraethoxysilane concentration and the relative molecular mass of polyvinylpyrrolidone on the microstructure of the rod-like silica were investigated.Rod-like SiO2-TiO2 core-shell particles were prepared by the liquid phase deposition method using the optimized rod-like silica particles.The rod-like SiO2-TiO2 core-shell particles were characterized by XRD,TEM and FTIR.The results show that the shape of silica particles gradually changes from being pin to rod with the increase of relative molecular mass of polyvinylpyrrolidone.The ratio of length to diameter of rod-like silica particles increases with the increasing concentration of tetraethoxysilane,and many spherical silica particles appear in the products.The crystal of titania coated on the surface of rod-like silica is anatase and the shape is needle.The thickness of this titania shell is about 80 nm.
Keywords：silica;titania;core-shell particle
