单分散双功能化复合二氧化硅微球的可控合成

在水溶液中,以硫氰基丙基三乙氧基硅烷(TCPTES)为前驱体,氨水为催化剂,合成了TC-SiO_2聚倍半硅氧烷微球。进一步以TC-SiO_2微球为核,用脲丙基三乙氧基硅烷(UDPTES)在其表面进行溶胶-凝胶反应,制备了TC-SiO_2@U-SiO_2双功能化核壳结构复合微球。通过扫描电子显微镜(SEM)、傅里叶变换红外光谱(FTIR)、热重(TG)对所得微球的形貌、结构及性能进行了表征。实验结果表明,十六烷基三甲基溴化铵(CTAB)的用量和包覆时间对所得双功能化微球TC-SiO_2@U-SiO_2的粒径和形貌有着重要影响。当CTAB为30mg,水、乙醇分别为20mL和7mL,TC-SiO_2球为40mg,氨水为0.3mL,UDPTES为0.6mL时,室温下反应20h,可制得粒径630~690nm且分散性良好的TC-SiO_2@U-SiO_2微球。

Controlled Synthesis of Highly Monodisperse Bifunctionalized Hybrid Silica Microspheres

In aqueous solution,highly monodisperse thiocyanatosilesquioxane (TC-SiO2 )microspheres were prepared successfully by using 3-thiocyanatopropyltriethoxysilane (TCPTES)as a precursor and ammonia hydroxide as a catalyst.Bifunctionalized hybrid silica core-shell microspheres (TCSiO2@U-SiO2 )were then synthesized via the sol-gel reaction between ureidopropyltriethoxysilane (UDPTES)and the as-synthesized TC-SiO2 microspheres.The morphology,structure and performance of the products were characterized by scanning electron microscopy(SEM), Fourier transform infrared spectroscopy (FTIR)and thermogravimetric analysis (TGA),respectively.The results showed that morphology and particle size of the bifunctional microspheres were greatly influenced by concentration of cetyltrimethylammonium bromide(CTAB)and reaction time.Highly monodisperse TC-SiO2 @U-SiO2 micospheres with diameter ranging from 630 nm to 690 nm could be prepared under a certain material proportion,i.e.30 mg CTAB,20 mL deionized water,7 mL ethanol,40 mg TC-SiO2 microspheres,0.3 mL ammonia,0.6 mL UDPTES, and areaction condition of 20 h stirring at room temperature.