纳米SiO_(2)修饰陶瓷中空纤维制备MCM-48分子筛膜  

MCM-48 membranes synthesized on ceramic hollow fibers with nano-sized SiO_(2) modification

作　　者：谢继贤 任生缘 周诗健 王学瑞 顾学红 XIE Jixian;REN Shengyuan;ZHOU Shijian;WANG Xuerui;GU Xuehong(State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]南京工业大学化工学院,材料化学工程国家重点实验室,南京211816

出　　处：《膜科学与技术》2021年第6期43-50,59,共9页Membrane Science and Technology

基　　金：国家自然科学基金重点项目(22035002);国家自然科学基金青年基金(21908097);江苏省特聘教授计划;江苏省“333人才工程”;江苏省研究生科研与实践创新计划项目(SJCX20-0362)。

摘　　要：采用擦涂纳米SiO_(2)颗粒的方法,修饰四通道α-Al_(2)O_(3)中空纤维载体表面,实现了高性能MCM-48分子筛膜的可控制备.通过对比不同修饰方法发现,擦涂纳米SiO_(2)颗粒能有效降低载体的表面粗糙度,同时避免了因内渗带来的载体传质阻力增加.经过两次水热合成,纳米SiO_(2)修饰中空纤维制备MCM-48分子筛膜厚度为3μm,脱除模板剂前N_(2)渗透性为4.17×10^(-11) mol/(m^(2)·s·Pa),表明膜层较为致密.脱除模板剂后,0.02 MPa下MCM-48分子筛膜的H_(2)渗透性为4.82×10^(-7) mol/(m^(2)·s·Pa),H_(2)/N_(2)理想选择性为3.60;努森扩散对于H_(2)渗透性的贡献为99.69%,符合努森扩散占主导的分离机理.等摩尔H_(2)/N_(2)双组分的分离选择性(2.90)低于理想选择性.孔度渗透实验表明膜平均孔径为2.94 nm,略大于MCM-48本征孔道尺寸.High selective mesoporous MCM-48 membranes were prepared on four-channelα-Al_(2)O_(3)hollow fiber with an average pore size of 400 nm.Prior to hydrothermal synthesis,different approaches were used to modify the hollow fibers.The results showed that the nano-sized SiO_(2) particles were effectively coated on the support surface,reducing the roughness without significant decrease of the gas permeation.The membrane synthesis was optimized based on the hollow fibers modified by rubbing nano-sized SiO_(2) particles.After twice hydrothermal synthesis,a dense membrane with thickness of 3μm was obtained.Because of the template accommodation,N_(2) permeance of the as-synthesized membrane was as low as 4.17×10^(-11) mol/(m^(2)·s·Pa).After removing the template,the H_(2) permeance reached 4.82×10^(-7) mol/(m^(2)·s·Pa)and the ideal H_(2)/N_(2) selectivity was 3.60.The H_(2) permeation was dominated by the MCM-48 pores,wherein 99.69%H_(2) permeance was contributed by Knudsen diffusion.The equimolar H_(2)/N_(2) mixture selectivity(2.90)was lower than the ideal selectivity.The average pore size of the membrane was determined to be 2.94 nm by permporometry,which was slightly larger than the intrinsic pore size of MCM-48(2.38 nm).

关 键 词：MCM-48 中空纤维 介孔分子筛 气体分离膜 

分 类 号：TQ028.8[化学工程]