Preparation technology of polyamide composite charged nanofiltration membrane

A new charged nanofiltration membrane was presented to apply in interfacial polymerization.The purpose is to coat a thin polypiperazing-amide layer onto polyethersuffone uhrafiltration membrane which has the morphology and functionality of nanofiltration membrane.Taking 2,5-diaminobenzene sulphonic acid(DIA) and trimesoyl chloride as reactive monomers,and using uniform design method,charged nanofiltration membrane was prepared by interfacial polymerization.The optimization preparation conditions are as follows: mass friction of DIA is 0.75%,that of SDS is 0.15 %,that of acid accepters(Na) is 0.15%,and the reacting time is 3 minutes.With the conditions,the retention rate of the membrane to NaCl and KCl both are 40%,that of the membrane to MgCl2 is 80%,and that of the membrane to the organic dyes with small molecule mass is more than 90%.