Preparation and separation properties of choline chloride modified polyamide nanofiltration membrane
In order to improve the separation performance of traditional polyamide(PA)nanofiltration membrane,a posi-tively charged quaternary ammonium salt choline chloride(CC)was introduced into the surface of polyamide nanofiltration membrane by the esterification reaction between acyl chloride and hydroxyl,and a nearly neutral charge CC/PA nanofiltration membrane was prepared under neutral conditions.The influence of mass fraction of CC on the performance of thin film composite(TFC)membrane was investigated by the separation test of inor-ganic salts.The results showed that when the mass fraction of CC reached 0.1%,the modification effect was the best.The TFC membrane has a high retention on Na2SO4,MgSO4 and MgCl2,and the separation ability of Mg2+/Li+was improved.After modification,the permeation flux of TFC membrane was increased by 315%.