三氟丙基修饰的有机-无机杂化二氧化硅膜制备、氢气分离及水热稳定性能  

Preparation, Gas Separation and Hydrothermal Stability Property of Organic-inorganic Hybrid Silica Membranes Modified by Trifluoropropyl Groups

作　　者：王学伟[1] 韦奇[1] 洪志发[1] 李群艳[1] 聂祚仁[1] 

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《化学学报》2012年第24期2529-2535,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.21171014;50502002);国家863计划(No.2009AA03Z213);浙江省绿色化学合成技术国家重点实验室培育基地开放基金(No.GCTKF2012016)资助~~

摘　　要：以三氟丙基三甲氧基硅烷(TFPTMS)和1,2-双(三乙氧基硅基)乙烷(BTESE)为前驱体,通过溶胶-凝胶法在酸性条件下制备三氟丙基修饰的有机-无机杂化SiO2膜材料,并深入研究三氟丙基修饰对溶胶粒径和疏水性能的影响以及膜材料的氢气渗透分离性能和长期水热稳定性.结果表明三氟丙基已成功修饰到有机-无机杂化SiO2膜材料中,且随着TFPTMS修饰量的增加,溶胶粒径有减小趋势,膜材料的疏水性能逐渐提高.当n(TFPTMS)/n(BTESE)=0.6时,溶胶平均粒径为2.11 nm,膜材料对水的接触角达到111.6°±0.7°.H2在修饰后膜材料中的输运主要遵循微孔扩散机理,300℃时H2的渗透率为8.86×10-7mol m-2 s-1 Pa-1,H2/CO2的理想分离系数达到5.4,且当进气摩尔比例为1∶1时H2/CO2的双组分气体分离系数达到了4.82,均高于Knudsen扩散分离因子(H2/CO2=4.69),膜材料呈现出良好的分子筛分性能.膜材料在250℃及水蒸气摩尔含量为5%的水热环境中能稳定工作300 h以上.Organic-inorganic hybrid silica membranes modified with trifluoropropyl groups were synthesized by acid-catalyzed co-hydrolysis and polycondensation reaction of （3,3,3-trifluoropropyl）trimethoxysilane （TFPTMS） and bridged silsesquioxane 1,2-bis（triethoxysilyl）ethane （BTESE） as co-precursors. The effect of trifluoropropyl groups on the sol particle size and the hydrophobic property, the hydrogen permeation and separation behavior and the hydrothermal stability of the obtained membranes were investigated in detail. The results show that trifluoropropyl groups have been successfully incorporated onto the surface of membranes. The sol particle size decreases gradually and hydrophobic properties of the modified silica membranes are enhanced with increasing amount of TFPTMS in the mixture. When the molar ratio of TFPTMS/BTESE increases to 0.6, the organic-inorganic hybrid silica membranes exhibit water contact angles of 111.6°±0.7° and a narrow sol particle size distribution centered at 2.11 nm. The transport of hydrogen in the modified hybrid silica membranes complies with a micropore diffusion mechanism, with a high hydrogen permeance of 8.86×10-7 mol·m-2·s-1·Pa-1, a H2/CO2 permselectivity of 5.4, and a H2/CO2 binary gas （molar ratio=1∶1） separation factor of 4.82 at 300 ℃, higher than the corresponding Knudsen value （H2/CO2=4.69）. The modified organic-inorganic silica membranes are hydrothermally stable while aging at a humid atmosphere with a temperature of 250 ℃ and a steam concentration of 5% for more than 300 hours.

关 键 词：三氟丙基 有机-无机杂化SiO2膜 氢气分离 水热稳定性 

分 类 号：TQ127.2[化学工程—无机化工]