以廉价硅源制备多孔二氧化硅微球及其孔结构的控制

Synthesis and Morphological Control of Porous Silica Spheres Using Inexpensive Silica Source

以水玻璃(硅酸钠溶液)作为起始硅源,通过阳离子交换树脂得到硅酸溶液,进而采用反相悬浮聚合法制备了多孔结构的二氧化硅微球,并考察了乳液放置时间以及碱热处理条件对于微球的形貌、比表面积、平均孔径及孔容的影响。实验发现,此方法可制备10～100μm球形圆整的二氧化硅微球,比表面积SBET可控变化区间为124.3～597.3 m2/g,平均孔径2.487～13.97 nm,孔容0.3354～0.8314 cm3/g。同时,利用基本粒子生长和堆砌的机理解释了不同孔结构形成的原因。为制备粒径和孔径可控的微米级二氧化硅球提供了一种成本低且简单有效的方法。

Water glass （sodium silicate solution） was chosen as silica source, which then transformed to silicic acid solution after treatment of cation exchange resin. Then porous SiO/spheres were prepared by reverse suspension polymerization. Effects of storage time after emulsion and base-dissolving treatment on the characters of SiO2 （size and distribution, specific surface area, average pore size and pore volume） were discussed. SiO2 spheres ranged from 10 μm to 100 μm could be prepared by this method, the specific surface area can be controlled from 124.3 m^2/g to 597.3 m^2/g, while the average pore size in the range of 2. 487 nm to 13.97 nm, pore volume 0. 3354 cm^3/g to 0. 8314 cm^3/g. The growth and aggregation of primary particles pathway was proposed for the formation mechanism of different pore structure. This method is economic, effective and easy to manipulate to prepare micro-sized SiO2 spheres with controllable diameters and pore sizes.