三嗪框架聚合物膜用于有机纳滤甲醇/正己烷分离  

Triazine framework polymer membranes for methanol/n-hexane separation via organic solvent nanofiltration

作　　者：吕阳光 左培培 杨正金 徐铜文[1] LYU Yangguang;ZUO Peipei;YANG Zhengjin;XU Tongwen(School of Chemistry and Materials Science,University of Science and Technology of China,Hefei 230026,Anhui,China)

机构地区：[1]中国科学技术大学化学与材料科学学院,安徽合肥230026

出　　处：《化工学报》2023年第4期1598-1606,共9页CIESC Journal

基　　金：国家自然科学基金项目(21922510)。

摘　　要：具备耐各种有机溶剂的微孔聚合物膜在有机纳滤领域逐渐受到重视。采用双氰基单体的超酸催化成环聚合反应,制备微孔框架聚合物薄膜(CTF-BP),该膜具备良好的力学性能,可耐受甲醇和正己烷等常见有机溶剂。CTFBP膜内大量<1.0 nm的微孔通道使膜具备良好的筛分性能,其截留分子量为550。膜内含有的三嗪结构与羟基具有较强的亲和性,使甲醇的跨膜通量[1.10 L/(m^(2)·h·bar)]显著高于黏度更低的正己烷通量[0.23 L/(m^(2)·h·bar)]。采用纳滤操作将膜用于分离含低浓度甲醇的正己烷溶液[含5%(质量)甲醇的正己烷溶液],结果显示甲醇/正己烷分离因子最高可达到1485,渗透液的总流量超过3.21 kg/(m^(2)·h)。证实CTF-BP膜有望实现高效甲醇/正己烷分离。Microporous polymer membranes resistant to various organic solvents have gradually attracted attention in the field of organic nanofiltration.Herein,we report a covalent triazine framework membrane(CTF-BP)synthesized by a super acid-catalyzed organo-sol-gel reaction of commercially available aromatic nitrile monomer.This membrane exhibits good mechanical strength and is dimensionally stable in organic solvents,such as methanol,n-hexane,etc.Size sieving by the robust micropores(<1.0 nm)confers the membrane with a cut-off molecular weight as low as 550.The hydrogen interaction between triazine rings and the hydroxyl groups facilitates the transport of methanol,the flux of which reaches up to 1.10 L/(m^(2)·h·bar),a value much higher than that of the less viscous n-hexane[0.23 L/(m^(2)·h·bar)].To demonstrate the practical applicability,this membrane is utilized to separate n-hexane containing low concentration of methanol solution[5%(mass)methanol],and a maximum separation factor of 1485 and a methanol flux of 3.21 kg/(m^(2)·h)are obtained.These results demonstrate the great potential of the CTF-BP membranes in the recovery of methanol from its mixture with n-hexane via organic solvent nanofiltration(OSN).

关 键 词：三嗪框架 聚合物膜 耐有机溶剂 纳滤 甲醇/正己烷分离 

分 类 号：TQ028.8[化学工程]