Titania coating on silica core particles was performed from monodisperse silica spheres with mean diameter of 800 nm using tetrabutyl titanate by St(o)ber method.The thickness of the titania coating layer was varied from 30 nm to 100 nm depending on the concentration of tetrabutyl titanate.After calcining the core-shell particles in air at 550 ℃ for 1 h,anatase titania coating layer was obtained suitable for scattering near infrared radiation.The preparation route is a modification of sol-gel method,i.e.a hydrothermal process is also involved.Additionally,it is a simple route without an added coupling agent or surfactant.%利用St(o)ber方法合成了平均粒径在800 nm,球形度、单分散性良好的SiO2微球,再将其作为制备核壳结构SiO2@TiO2颗粒的内核.利用钛酸四丁酯水解反应,在SiO2内核上包覆制备了壳厚在30～100 nm的TiO2壳层,TiO2壳层厚度可根据水解反应中钛酸四丁酯的量调控.将制得的SiO2@TiO2核壳结构颗粒在550℃煅烧1h,氧化钛壳层的晶型转变为锐钛矿相,晶型转变为锐钛矿相的TiO2更适合作为填料应用于近红外反射涂层.本文合成厚度可控SiO2@TiO2微球的方法是一种改进的溶胶凝胶方法,即在溶胶凝胶方法的基础上增加水热合成工艺.另外,本合成方法工艺简单,无表面活性剂或者耦合剂的引入.
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