Wang Zhaojia, Hao Liwei, Yang Feihua, Wei Qi
State Key Laboratory of Solid Waste Reuse for Building Materials, 69 Jinding North Road, Shijingshan District, Beijing 100041, China.
College of Materials Science and Engineering, Beijing University of Technology, 100 Pingleyuan, Chaoyang District, Beijing 100124, China.
Membranes (Basel). 2020 Apr 15;10(4):70. doi: 10.3390/membranes10040070.
It is of great significance to separate hazardous methyl tert-butyl ether (MTBE) from water in terms of environmental protection and human health. In the present work, α-AlO-suppotred silica membranes were prepared by the sol-gel and dip-coating technique. Two fluorinated alkylsilanes (1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFOTES) and trifluoropropyltriethoxysilane (TFPTES)) and two non-fluorinated alkylsilanes (octyltriethoxysilane (OTES) and propyltriethoxysilane (PTES)) were adopted to silylate the silica membrane by the post-grafting method which is used for the separation of MTBE from water by pervaporation. The results show that silylation enhances the hydrophobicity of silica membranes. The silylated silica membranes are selective towards MTBE, and the MTBE/water separation factor varies with grafting agents in the order: PFOTES > TFPTES > OTES > PTES. Membranes silylated with fluorinated carbon chains seem to be more selective towards MTBE than those with non-fluorinated carbon chains. The total flux is proportional to the pore volume of silica membranes, which depends on grafting agents in the order: PTES > PFOTES > OTES > TFPTES. Considering both total flux and selectivity, the PFOTES-SiO membrane is most effective in separation, with a MTBE/water separation factor of 24.6 and a total flux of 0.35 kg m h under a MTBE concentration of 3.0% and a feed temperature of 30 °C.
从环境保护和人类健康的角度来看，从水中分离有害的甲基叔丁基醚（MTBE）具有重要意义。在本工作中，采用溶胶-凝胶和浸涂技术制备了α-AlO负载的二氧化硅膜。采用两种氟化烷基硅烷（1H,1H,2H,2H-全氟辛基三乙氧基硅烷（PFOTES）和三氟丙基三乙氧基硅烷（TFPTES））和两种非氟化烷基硅烷（辛基三乙氧基硅烷（OTES）和丙基三乙氧基硅烷（PTES））通过后接枝法对二氧化硅膜进行硅烷化处理，该方法用于通过渗透蒸发从水中分离MTBE。结果表明，硅烷化提高了二氧化硅膜的疏水性。硅烷化的二氧化硅膜对MTBE具有选择性，MTBE/水分离因子随接枝剂的变化顺序为：PFOTES > TFPTES > OTES > PTES。用氟化碳链硅烷化的膜对MTBE的选择性似乎比用非氟化碳链硅烷化的膜更高。总通量与二氧化硅膜的孔体积成正比，孔体积取决于接枝剂的顺序为：PTES > PFOTES > OTES > TFPTES。综合考虑总通量和选择性，PFOTES-SiO膜在分离方面最有效，在MTBE浓度为3.0%、进料温度为30°C时，MTBE/水分离因子为24.6，总通量为0.35 kg m⁻² h⁻¹。
