Removal of metal ions from water can not only alleviate the scaling problem of domestic and industrial water,but also solve the water safety problem caused by heavy metal ion pollution.Here,we fabricate a positively c...Removal of metal ions from water can not only alleviate the scaling problem of domestic and industrial water,but also solve the water safety problem caused by heavy metal ion pollution.Here,we fabricate a positively charged nanofiltration membrane via surfactant-assembly regulated interfacial polymerization(SARIP)of 2-methylpiperazine(MPIP)and trimesoyl chloride(TMC).Due to the existence of methyl substituent,MPIP has lower reactive activity than piperazine(PIP)but stronger affinity to hexane,resulting in a nanofiltration(NF)membrane with an opposite surface charge and a loose polyamide active layer.Interestingly,with the help of sodium dodecyl sulfate(SDS)assembly at the water/hexane,the reactivity between MPIP and TMC was obviously increased and caused in turn the formation of a positively charged polyamide active layer with a smaller pore size,as well as with a narrower pore size distribution.The resulting membrane shows a highly efficient removal of divalent cations from water,of which the rejections of MgCl_(2),CoCl_(2)and NiCl_(2)are higher than 98.8%,98.0%and 98.0%,respectively,which are better than those of most of other positively charged NF membranes reported in literatures.展开更多
基金This work was supported by the National Key Research and Development Program of China(No.2019YFA0705800)the National Natural Science Foundation of China(Nos.21988102,51873230)+1 种基金the National Natural Science Funds for Distinguished Young Scholars of China(No.51625306)the Youth Innovation Promotion Association of Chinese Academy of Sciences.
文摘Removal of metal ions from water can not only alleviate the scaling problem of domestic and industrial water,but also solve the water safety problem caused by heavy metal ion pollution.Here,we fabricate a positively charged nanofiltration membrane via surfactant-assembly regulated interfacial polymerization(SARIP)of 2-methylpiperazine(MPIP)and trimesoyl chloride(TMC).Due to the existence of methyl substituent,MPIP has lower reactive activity than piperazine(PIP)but stronger affinity to hexane,resulting in a nanofiltration(NF)membrane with an opposite surface charge and a loose polyamide active layer.Interestingly,with the help of sodium dodecyl sulfate(SDS)assembly at the water/hexane,the reactivity between MPIP and TMC was obviously increased and caused in turn the formation of a positively charged polyamide active layer with a smaller pore size,as well as with a narrower pore size distribution.The resulting membrane shows a highly efficient removal of divalent cations from water,of which the rejections of MgCl_(2),CoCl_(2)and NiCl_(2)are higher than 98.8%,98.0%and 98.0%,respectively,which are better than those of most of other positively charged NF membranes reported in literatures.
