十七氟癸基修饰的疏水二氧化硅膜材料的制备及氢气分离性能  

Preparation and hydrogen separation of hydrophobic silica membranes modified by perfluorodecyl group

作　　者：丁元利[1] 韦奇[1] 刘相革 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：《膜科学与技术》2014年第6期22-27,共6页Membrane Science and Technology

基　　金：国家自然科学基金资助项目(21171014;50502002);国家"863"计划课题(2009AA03Z213);北京市教委科技计划重点项目资助(KZ201410005006)

摘　　要：通过溶胶-凝胶法,以正硅酸乙酯(TEOS)和十七氟癸基三乙氧基硅烷(PFDTES)为前驱体,在酸性和洁净室条件下制备了十七氟癸基修饰的SiO2膜材料,分别通过动态光散射技术、接触角测量、红外光谱以及热重分析等测试手段对溶胶的粒径分布及膜材料的疏水性能进行了表征,并深入研究了十七氟癸基修饰后膜材料的氢气渗透和分离性能.结果表明,当摩尔比n(PFDTES)/n(TEOS)=0.2时,溶胶的粒径狭窄分布在3.9nm.十七氟癸基已成功修饰到SiO2膜材料中,十七氟癸基的修饰使得膜材料从亲水性变为疏水性,在上述摩尔比例下,膜材料对水的接触角达到112.0°±0.6°.H2的单组分渗透率随温度的升高而增大,300℃时达到10.00×10-7 mol/(m2·s·Pa),H2/CO2的单组分理想分离系数及双组分分离系数分别达到6.10和13.30,均高于其Knudsen扩散分离因子(4.69),H2在膜材料中的输运主要遵循活化扩散机理.A sol-gel technique was used to synthesize perfluorodecyl-modified silica membranes with tetraethyl orthosilicate（TEOS）and 1H,1H,2H,2H- perflouorodecyltriethoxysilane（PFDTES）as precursors under acidic and clean room conditions.The particle size distribution of silica sols and the hydrophobic properties of modified silica membranes were characterized by means of dynamic light scattering（DLS）,water contact angle measurement,Fourier translation infrared spectroscopy（FT-IR）and thermo gravimetric analysis（TG）.The hydrogen permeation and separation performance of modified silica membranes were also investigated in detail.The results show that when the molar ratio of PFDTES/TEOS reaches 0.2,the modified silica sols have a particle size centered at 3.90 nm,which is extremely suitable for dip-coating.Perfluorodecyl groups have been successfully incorporated and hydrophobic silica membranes with a water contact angle of 112.0°±0.6°are obtained at above-mentioned molar ratio.The hydrogen transport in modified silica membranes complies predominantly with activated diffusion mechanism,as demonstrated by the fact that the hydrogen permeance increases with increasing temperatures.At the temperature of 300 ℃,the modified membranes exhibit a significantly high H2 permeance of 10.00×10^-7 mol/（m^2·s·Pa）,a H2/CO2 permselectivity of 6.10 and a H2/CO2 binary gas mixture separation factor of 13.30,higher than that of Knudsen diffusion（4.69）.

关 键 词：十七氟癸基 溶胶-凝胶法 疏水SiO2膜 氢气分离 

分 类 号：TQ051.893[化学工程]