聚吡咯-壳聚糖改性制备单价选择性阳离子交换膜

Preparation of univalent selective cation exchange membrane by modification of polypyrrole-chitosan

以体积比为1:1的聚吡咯和壳聚糖混合液浸渍改性普通均相阳离子交换膜,再通过2.5%戊二醛交联制备具有单价选择性能的阳离子交换膜.通过静态电渗析实验考察氧化剂种类、氧化剂浓度、浸渍时长、交联时长等因素对改性膜分离性能的影响,确定了最佳改性条件:氧化剂为0.8mol/L的Na_(2)S_(2)O_(8),浸渍时间为6h,交联时间为16h.改性后膜表面更加平整,离子交换容量为0.93mmol/g,含水率、溶胀度分别为13.92%、9.95%,接触角为103.03°,化学稳定性显著提高.静态电渗析2h后H^(+)的透过率为79.98%,Zn^(2+)的泄漏率仅为1.59%,选择透过性系数达到50.24.

The common homogeneous cation exchange membrane was impregnated with a mixture of polypyrrole and chitosan at a volume ratio of 1:1,and then crosslinked with 2.5%glutaraldehyde to prepare the cation exchange membrane with monovalent selectivity.The effects of oxidizer type,oxidizer concentration,impregnation time and crosslinking time on the separation performance of the modified membrane were investigated by static electrodialysis test.The optimal modification conditions were determined as follows:oxidizer was 0.8 mol/L Na_(2)S_(2)O_(8),impregnation time was 6h,crosslinking time was 16h.After modification,the surface of the membrane is smoother,the ion exchange capacity is 0.93mmol/g,the water content and swelling degree are 13.92%and 9.95%,respectively,and the contact Angle is 103.03°.The chemical stability of the membrane is significantly improved.After 2hours of static electrodialysis,the transmittance of H^(+)was 79.98%,the leakage rate of Zn^(2+)was only 1.59%,and the selective transmittance coefficient reached 50.24.