磺化嵌段共聚物接枝改性制备高通量渗透汽化脱盐膜  

Preparation of high flux pervaporation desalination membranes via side-chain modification of sulfonated block copolymers

作　　者：曾飞祥 李娜 延檬羽 纪松灿 王子恒 ZENG Fei-xiang;LI Na;YAN Meng-yu;JI Song-can;WANG Zi-heng(Shaanxi Key Laboratory of Energy Chemical Process Intensification,School of Chemical Engineering and Technology,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学化学工程与技术学院,陕西省能源化工过程强化重点实验室,陕西西安710049

出　　处：《高校化学工程学报》2020年第5期1159-1166,共8页Journal of Chemical Engineering of Chinese Universities

基　　金：国家自然科学基金(21676210)。

摘　　要：为了提高渗透汽化脱盐膜的水通量,对聚苯乙烯-乙烯/丁烯-苯乙烯(SEBS)嵌段共聚物进行改性,通过侧链接枝聚苯乙烯增多磺化位点,制备出一种新型的磺化嵌段共聚物膜材料(S-SEBS-g-PSt),磺化度为33%~50%。结果表明,改性后膜的水通量提高了25%。当磺化度为50%时,水通量为28.4 kg×m^-2×h^-1,并保持高达99.9%盐截留率。采用分子动力学模拟研究S-SEBS-g-PSt膜的微观结构以及水和盐在膜内的扩散特性。在温度为338 K下,磺化度从33%提高到50%时,膜内亲水区域宽度从1.8增加到2.4 nm,水分子在膜内的扩散系数由2.26×10^-9提高到3.11×10^-9m^2×s^-1。结果表明,侧链接枝有效调控膜内微相分离结构和传递通道,提高水分子输运能力,提升嵌段类聚合物膜在脱盐和水处理领域的应用潜力。In order to improve water flux of pervaporation desalination membranes,polystyrene was grafted onto poly(styrene-ethylene/butene-styrene)(SEBS)block copolymers to prepare a new sulfonated block copolymer membrane material(S-SEBS-g-PSt)with 33%-50%sulfonation degree.The results show that the water flux of the S-SEBS-g-PSt membrane is increased by more than 25%after modification.With 50%sulfonation degree,the membrane shows a high water flux of 28.4 kg×m^-2×h^-1 and a high salt retention of 99.9%.The microstructure and water/salt diffusivity of the membrane was investigated by molecular dynamics(MD)simulation.When the sulfonation degree was increased from 33%to 50%,the size of the hydrophilic domain in the membrane increased from 1.8 to 2.4 nm,and the water diffusion coefficient increased from 2.26×10^-9 to3.11×10^-9 m^2×s^-1 at 338 K.Side chain grafting can effectively regulate the structure of the micro-phase separation structure and nano-channels for mass transport,improve the transport capacity for water molecules,and enhance the application potential of block copolymer membranes in desalination and water treatments.

关 键 词：嵌段共聚物 侧链改性 磺化 脱盐 扩散系数 

分 类 号：TQ465.92[化学工程—制药化工]