摘要
以1,2-二(三乙氧基硅基)乙烷为前驱体,通过溶胶-凝胶法合成出稳定的纳米复合SiO2溶胶,采用浸浆法在具有γ-Al2O3/α-Al2O3结构的片状载体上涂膜,然后在N2气氛下烧成得到完整无缺陷的有机-无机复合SiO2膜.以TG/DSC、BET和气体渗透性能测试等手段对复合SiO2膜及粉体进行了表征.该膜对小分子气体(He、CO2、O2、N2、CH4和SF6)的分离表现出分子筛分效应,对He的渗透通量为(1.0～3.5)×10-7mol/(m2·s·Pa)(200℃,0.3MPa).500℃烧成的膜对He/CO2的理想分离因子为47,远远高于Knudsen扩散时He/CO2的理想分离因子(3.3).详细考察了烧成温度对膜水热稳定性的影响.结果表明:在450、500和550℃三个温度下烧成的膜水蒸气稳定条件(分压)分别为200、500和1000kPa。
A new organic-inorganic hybrid microporous membrane was prepared via Sol-Gel method with bridged silsesquioxane（1,2-bis（triethoxysilyl）ethane,BTESE） as a precursor.Macroporous α-Al2O3 disk supported mesopo-rous γ-Al2O3 layer was used as support.Defect-free hybrid silica membrane was deposited on such support by using a stable nano-sized sol and subsequently calcining in pure nitrogen atmosphere.The hybrid SiO2 membrane as well as the powder was characterized by TG/DSC,BET and gas permeation.The hybrid silica membranes exhibit molecular sieve properties for small gases like He,CO2,O2,N2,CH4,and SF6 with helium permeance in the range of（1.0-3.5）×10^-7mol/（m^2·s·Pa）（at 200℃,0.3MPa）.Considering the membrane calcined at 500℃,it is found that the permselectivity of the He（0.255nm） with respect to CO2（0.33nm） is 47,which is much higher than the corresponding Knudsen value（He/CO2=3.3）.Effect of calcination temperature on hydrothermal stability of those microporous membranes was studied in detail.Results show that the performances of hybrid SiO2 membranes calcined at 450℃,500℃ and 550℃ deteriorate under a H2O partial pressure of 200,500 and 1000kPa,respectively.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第7期758-764,共7页
Journal of Inorganic Materials
基金
国家重点基础研究发展计划(2009CB623400)
国家自然科学青年基金(20906047)
材料化学工程联合国家重点实验室开放课题(SKL-ChE-09A01)
南京市留学回国人员基金
关键词
微孔陶瓷膜
有机-无机复合SiO2膜
水热稳定性
气体分离
microporous ceramic membrane
hybrid organic-inorganic SiO2 membrane
hydrothermal stability
gas separation
