中文摘要：

以正硅酸乙酯（TEOS）、甲基三乙氧基硅烷（MTES）为硅源，硝酸为催化剂，制备了甲基修饰的二氧化硅膜，研究了MTES改性二氧化硅膜的表面润湿性与表面结构的关系以及MTES改性二氧化硅膜的吸水率。用已知表面张力的液体测定接触角，按扩展的Fowkes式计算试样的表面张力γs及其三组分值γs^d（色散力）、γs^p（偶极矩力）和ysn（氢键力），用热重分析（TG）法测定二氧化硅膜的吸水率。结果表明，随着MTES／TEOS摩尔比增大，二氧化硅膜的表面自由能显著减小，表面润湿性降低，主要是表面张力中氢键力组分的贡献。x射线光电子能谱分析表明，这是由于二氧化硅颗粒表面sicH。基团增加而Si-O和0H基团减小所致。随着MTES／TEOS摩尔比增大，二氧化硅膜的吸水率降低，疏水性二氧化硅膜的MTES／TEOS摩尔比应大于0．8。

英文摘要：

Silica membranes modified with methyltriethoxysilane （MTES） have been prepared by acid- catalyzed co-hydrolysis and condensation reactions of tetraethylorthosilicate （TEOS） and MTES. The surface wettability, surface structure and water absorbed amount of the silica membranes were investi- gated. The contact angles of the samples were measured, The values of dispersion force γs^d , dipole force ）＇sp and hygrogen bonding force γsh to the surface tensions for the silica membranes were evalua- ted by the extended Fowkes equation. Mainly because of the contribution of hygrogen bonding force, the surface free energy and surface wettability of the silica membranes decrease greatly with increasing MTES/TEOS ratio. X-ray photoelectron spectroscopy （XPS） shows that the reason was the increase of Si--CH3 functional group and the decrease of Si O and O--H functional groups on the surface of silica membranes. The physisorbed water amount decreases with the MTES/TEOS ratio increased. The MTES/TEOS ratio for hydrophobic silica membrane should be above 0.8.