溶胶-凝胶法制备Si掺杂TiO_2超滤膜

Fabrication of Si-doped TiO_2 ultrafiltration membranes by sol-gel process

以钛酸四丁酯为Ti源、正硅酸乙酯为Si源、乙酰丙酮为螯合剂、HNO3为催化剂、P123为模板剂,采用溶胶-凝胶法制备Si掺杂的TiO2介孔材料。利用低温N2吸附-脱附法、X线衍射仪(XRD)、透射电子显微镜(TEM)等考察Si掺杂量对TiO2材料的微观结构及晶体结构的影响。结果表明:Si的最佳掺杂量n(Si)/n(Ti)=0.05,且Si的引入阻碍了TiO2材料组装孔的坍塌,抑制了TiO2材料的晶型转变温度,同时提高了TiO2材料的比表面积。选用最佳Si掺杂量溶胶为涂膜液,通过过滤实验表征,3次涂膜后的TiO2片式膜的纯水通量为3.6×10-5L/(m2·h·Pa),截留相对分子质量为19 900。

Using tetrabutyl titanate and tetraethyl silicate as precursors,HNO3as catalyst and P123 as template,mesoporous TiO2materials were synthesized by sol-gel route. The influence of Si / Ti molar ratio on the microstructure of TiO2materials was investigated by N2adsorption-desorption isotherm analysis,Xray diffraction（ XRD）,and transmission electron microscopy（ TEM）. Results showed that the best n（ Si） / n（ Ti） = 0. 05,the Si-doping in the titanium inhibited the TiO2phase transformation and the rapid growth of the crystals,and prevented the collapse of the assembled pores during the calcination process with the increasing of specific surface area. The Si concentration of 5% was used to fabricate the plate of TiO2ultrafiltration membrane. Filtration experiments showed that,after the three spin-coating,the pure water flux of TiO2ultrafiltration membrane was 3. 6 × 10^- 5L /（ m^2·h·Pa） with a cut-off molecular weight of 19 900.