利用甲基纤维素辅助合成介孔二氧化硅微球

Preparation of micrometer-sized mesoporous silica spheres assisted by methyl cellulose

通过调节硅酸四乙酯(TEOS)和嵌段聚合物F127(EO106PO70EO106)体系的pH值调控TEOS水解的速度,并利用甲基纤维素(MC)在水热条件下形成网格状液晶微滴结构的特点,一步诱导硅胶初级粒子聚沉制备微米级介孔氧化硅微球。研究了溶胶-凝胶的温度、pH值对成球性和孔结构的影响,通过氮吸附(BET),X射线衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、马尔文激光粒度分析(Malven)等手段分析表征了介孔氧化硅微球的形貌和孔结构,实验结果表明通过向TEOS和F127体系中加入MC,在pH=1、80℃条件下一步水热晶化可以合成直径在4～6μm、比表面积为450m2·g-1、孔径为4.2nm的介孔氧化硅微球。

Based on the methyl cellulose＇s （MC） function of forming liquid crystal in aqueous solution, the micrometer-sized mesoporous silica spheres with good dispersivity were synthesized in one step by adding MC into the aqueous solution containing F127 and TEOS （tetraethyl orthosilicate） with the appropriate pH. The effects of temperature and pH were investigated. It was found that in suitable synthesis condition （pH = 1 and 80℃of hydrothermal temperature） mesoporous silica spheres possessing 4.2 nm of pores diameter, 450 m^2·g^-1 of specific area and 4--6 μm of particle diameter were synthesized.