在溶胶-凝胶反应过程中,用乙烯基三乙氧基硅烷(TEVS)代替部分正硅酸乙酯(TEOS),通过两者共水解缩合反应制备乙烯基修饰的SiO_2膜,并通过BET、TG、NMR、以及接触角测量仪对所制备的材料进行表征.结果表明:修饰后的二氧化硅膜仍保持微孔结构,且孔径集中分布在0.5~0.7nm之间.由于部分亲水表面羟基被疏水乙烯基团所代替,乙烯基修饰的SiO2膜疏水性能得到明显提高,并且随着TEVS加入量的增加,疏水性能逐渐增强.
Ethylene-modified microporous silica membranes were prepared by acid catalysed cohydrolysis and condensation reaction of tetraethylorthosilicate(TEOS) and ethylenetriethoxysilane (TEVS) in ethanol and characterized by means of N2 adsorption, TG, NMR and contact angle meter. The results show that the modified materials remain a desirable microporous structure with a pore width centered at 0.5-0.7nm, and that the hydrophobic property of modified silica membranes is considerably improved due to the gradual replacement of hydrophilic silanol by hydrophobic ethylene on the surface with increasing molar ratio of TEVS/TEOS.