介孔-大孔双孔结构二氧化硅块状材料的合成

SYNTHESIS OF MONOLITHIC SILICA MATERIALS WITH MESOMACRO-POROUS DOUBLE-PORE STRUCTURE

以正硅酸乙酯、聚乙二醇、碳粉、乙醇、水和氨水为主要原料,用溶胶凝胶法通过压块成型工艺制备了具有介孔大孔双孔结构的块状SiO2多孔材料。研究了不同处理温度下样品的红外光谱、差热与热重曲线和孔结构。结果表明:600℃的热处理工艺可以除去样品中的聚乙二醇和碳粉,使之形成硅氧网络结构,得到介孔平均孔径为16～17nm、大孔孔径约为10μm的介孔大孔双孔结构SiO2块状材料。

Silica monoliths with meso-macro-porous double-pore structure were successfully synthesized with tetraethyl orthosilicate, polyethylene glycol, carbon powders, ethanol, water, and ammonia by the molding technology via a sol - gel method. Infrared spectra, thermogravimetry and differential thermal analysis curves, and pore structures of the samples made at different temperatures were studied. Results indicate that the mesopores with pore diameters of 16-17 nm and macropores with a pore diameter of 10 μm are formed during heating process from the removal of polyethylene glycol and carbon powders at 600℃. Meanwhile, a monolithic material of vitreous structure with Si-O bonds is formed.