手性选择性阳离子交换膜的制备及其评价

Preparation and Evaluation of Chiral Selective Cation-Exchange Membranes

以聚乙烯醇(PVA)为基材,加入β环糊精(β-cyclodextrin,β-CD)作为手性选择剂,加入聚丙烯酸(PAA)促进离子传递,制得具有手性选择性的阳离子交换膜(chiral selective cation-exchange membrane,CSCM)。通过电渗析过程拆分DL-对羟基苯甘氨酸(DL-4-hydroxyphenylglycine,DL-HPG)外消旋混合物以评价该膜的手性拆分效果。结果表明在酸性条件下D-对羟基苯甘氨酸优先通过手性阳离子交换膜,两种手性阳离子交换膜的选择性系数分别为1.21和1.34,验证了该膜的手性拆分效果。作为对比实验,还进行了料液中添加与不添加β环糊精,并以普通阳膜(cation-exchange membrane,CM)为分离介质时的电渗析实验,结果进一步验证了该膜的手性选择性来源于β环糊精。

Chiral selective cation-exchange membranes were prepared by blending poly （vinyl alcohol） as basic material, β-cyclodextrin as chiral selector and polyacrylic acid as ion-exchange material. Electrodialysis process for the separation of DL-4-hydroxyphenylglycine racemic mixture was carried out to evaluate these chiral selective cation-exchange membranes. Results show that D-4-hydroxyphenylglycine is preferentially transported through the chiral selective cation-exchange membranes in acidic medium. The selective factors of two kinds of chiral selective cation-exchange membranes are 1.21 and 1.34, respectively. As comparison, electrodialysis experiments using conventional cation-exchange membranes with or without adding β-cyclodextrin in feed were explored. These experiments verify that the chiral selectivity of chiral selective cation-exchange membranes originates from β-cyclodextrin.