基于PVDF-co-HFP制备具有阻酸性能的交联型阴离子交换膜的研究

A cross-linked anion exchange membrane with acid block performance was prepared based on PVDF-co-HFP

传统阴离子交换膜在电渗析酸浓缩过程中存在着严重的氢离子泄露.在此,我们采用PVDF-co-HFP作为聚合物主链,乙烯基咪唑作为功能基团,通过不同刚柔性交联剂的加入制备了系列交联型阻酸阴离子交换膜AEM-x(x=1、2、3)并研究了阻酸膜与传统阴离子交换膜在酸浓缩过程中的不同.通过红外等表征手段证实了所制备膜的理化性质.在电渗析过程中,AEM-x相较于普通的阴离子交换膜AHA具有更好的阻酸性能,其酸浓缩6 h后H^(+)浓度分别为0.64、0.68和0.74 mol/L均大于AHA(0.49 mol/L).特别是,AEM-3具有更好的酸浓缩性能,这表明了更稳定的交联结构有利于膜结构的稳定性,从而使得膜具有更好的阻酸性能.研究结果表明,所制备的交联型阴离子交换膜在酸浓缩领域具有广阔的应用前景.

The traditional anion exchange membrane has serious proton leakage during the acid concentration process of electrodialysis.Here,we used PVDF-co-HFP as the polymer backbone and vinylimidazole as the functional group to prepare a series of cross-linked acid-blocking anion-exchange membranes AEM-x(x=1,2,3)and studied the difference between the acid-blocking membrane and the traditional anion-exchange membrane in the acid concentration process.The physical and chemical properties of the prepared membranes were confirmed by infrared and other characterization methods.In the process of electrodialysis,AEM-x has better acid-blocking performance than the traditional anion exchange membrane AHA,H^(+)concentration after acid concentration for 6 h is 0.64 mol/L,0.68 mol/L and 0.74 mol/L,which are higher than those of AHA(0.49 mol/L respectively).In particular,AEM-3 has better acid concentration performance.It indicates that the more stable cross-linked structure is beneficial to the stability of the membrane structure making the membrane have better acid blocking performance.The research results imply that the prepared cross-linked anion exchange membrane has broad application prospects in the field of acid concentration.