摘要
传统纳滤膜主要通过界面聚合法制备,其分离层与基膜之间的结合力为分子间作用力,较为薄弱.通过在分离层与基膜之间引入配位键,采用金属-有机配位技术在聚酰亚胺基膜上制备了具有纳滤性能的分离层,首先通过考察NaOH溶液的浓度和反应时间对于基膜形貌和基团的影响,优化基膜的修饰程度,确定最佳的NaOH溶液浓度为0.01 mol/L,修饰时间为9 min.然后通过Fe^(3+)与Na+之间的置换将配位中心Fe^(3+)引入基膜表面.最后考察不同金属配位中心与有机配体的比例对膜性能的影响,确定最优植酸与Fe^(3+)的摩尔比为3:7.制得的配位纳滤膜表面负电性与亲水性都得到增强.制得的膜对1000mg/L Na_(2)SO_(4)的截留率为85.6%,通量为53 L/(m^(2)·h·MPa),对多种染料的截留率在99%以上,且具有较好的长期稳定性.
Traditional thin-film composite nanofiltration membranes fabricated by interfacial polymerization possess intermolecular force as the interaction between the active layer and substrate.This may lead to the peel-off of the active layer during the working process.In this work,based on the introduction of the coordination bond between the active layer and substrate,the active layer with nanofiltration performance was fabricated on a polyimide substrate by metal-organic coordination technology.Firstly,the modification degree of the substrate was optimized by investigating the effect of the NaOH concentration and the reaction time on the morphology and functional groups of the substrate surface.The optimum concentration and reaction time are 0.01 mol/L and 9 min respectively.Then,the coordination center Fe^(3+) was introduced to the substrate by replacing the Na+on the modified substrate with Fe^(3+),Finally,the effect that the ratio of metal coordination centers and organic ligands has on the membrane performance were studied,and the optimized mole ratio of PA and Fe^(3+)is 3:7.The hydrophilicity and negative charge of the obtained membrane are both enhanced.The rejection and permeability of the coordination nanofiltration membrane towards 1000 mg/L NaS_(2)O_(4) solution is 85.6%and 53 L/(m^(2)·h·MPa)respectively.Additionally,the membranes have a high rejection towards a variety of dyes and excellent long-term stability.
作者
王乾
王广睿
赵寅
孙世鹏
WANG Qian;WANG Guangrui;ZHAO Yin;SUN Shipeng(State Key Laboratory of Materials-Oriented Chemical Engineering,College of Chemical Engineering,Nanjing Tech University,Nanjing 211816,China)
出处
《膜科学与技术》
CAS
CSCD
北大核心
2021年第2期1-8,共8页
Membrane Science and Technology
基金
国家自然科学基金面上项目(21878146)
江苏省自然科学基金杰出青年项目(BK20190037)。
关键词
纳滤膜
配位膜
界面耦合
表面修饰
nanofiltration
coordination membrane
interfacial coupling
surface modification
