Regulation of carboxyl density in polyamide nanofiltration membranes and study of anti-fouling performances
This study employed trimesoyl chloride,isophthaloyl chloride,and piperazine to conduct interfacial polymerization,resulting in polyamide nanofiltration membranes with varying carboxyl group densities.The impact of carboxyl group density on membrane fouling and separation performance of magnesium and lithium were thoroughly investigated.The results revealed that the carboxyl group density in trimesoyl chloride-based membrane(TMC)was three times higher than that in isophthaloyl chloride-based membrane(IPC).Furthermore,the flux of TMC,IPC membranes were 81.9 L/(m2·h·MPa)and 56.5 L/(m2·h·MPa),respectively.Notably,the TMC membrane exhibited superior retention for magnesium sulfate and sodium chloride compared to the IPC membrane,achieving a retention rate of 82.66％for magnesium in brine and-27.82％for lithium.Moreover,the membrane fouling indicated that the irreversible flux reduction rates of the TMC membrane was three times higher than that of the IPC membrane,suggesting an inverse correlation between anti-fouling capability and carboxyl group density on membrane surfaces.These results validate the pivotal role of surface carboxyl functional groups in membrane fouling,providing critical insights for the development of anti-fouling and highly selective nanofiltration membranes.
nanofiltrationcarboxyl groupmembrane foulingsalt lake brine
NETL
NSTL
万方数据
