基于功能化离子液体的高性能纳滤膜的制备及性能研究

Preparation and Performance of High-Performance Nanofiltration Membranes Based on Functionalized Ionic Liquids

选用1-胺丙基-3-甲基咪唑溴盐(AMIB)作为水相添加剂,通过界面聚合制备了高性能纳滤膜,通过傅里叶变换红外光谱仪和X射线光电子能谱分析膜化学组成,通过扫描电子显微镜观察改性前后膜的表面和截面形貌变化,通过原子力显微镜观察膜的粗糙度变化,通过水接触角测试仪对改性前后膜表面亲水性进行对比,采用错流过滤平板膜测试仪对改性前后膜的分离性能和水通量进行测试。结果表明:与未改性纳滤膜相比,改性膜结构更疏松、膜厚更薄,表面变得亲水,改性膜在对Na_(2)SO_(4)保持在99%的高水平截留下,水通量大幅提升,从改性前的50.27 L/(m^(2)·h)提升到75.97 L/(m^(2)·h),长期稳定性优异。进一步对AMIB复合改性纳滤膜的结构与性能联系机理进行了探讨,为制备高性能纳滤膜提供了新的思路和方法。

1-aminopropyl-3-methylimidazole bromide(AMIB)was used as an aqueous additive to prepare highperformance nanofiltration membranes by interfacial polymerization.The chemical composition of the membranes was analyzed by Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy,and the changes in the surface and cross-section morphology of the membranes before and after the modification were observed by scanning electron microscope.The changes in the roughness of the membranes were observed by atomic force microscope,and the membrane surface hydrophilicity before and after modification was compared by water contact angle tester.The separation performance and water flux of the membrane before and after modification were tested by staggered-flow filtration flatplate membrane tester.The results showed that compared with the unmodified NF membranes,the modified membranes had a looser structure,a thinner membrane thickness,and the surface became hydrophilic.The modified membranes maintained a high level of 99%rejection of Na_(2)SO_(4) while the water flux was greatly increased from 50.27 L/(m^(2)·h)before modification to 75.97 L/(m^(2)·h).The long-term stability was excellent.The mechanism linking the structure and performance of AMIB composite modified nanofiltration membranes was further explored,which provided new ideas and methods for the preparation of high-performance nanofiltration membranes.