基于中空PDA⊂MOF/丝素纳米纤维复合材料的高通量高选择性水处理膜

Integration of PDA Decorated Hollow MOFs and Silk Nanofibers for Constructing Water Treatment Membrane with High Flux and High Selectivity

重金属离子和核废料污染饮用水是一个世界范围内长期存在的问题,对公众健康造成严重威胁,现有的净化方法往往不能快速和经济地解决这个问题。本研究制备了一种由中空金属有机框架(MOF)复合材料和丝素纳米纤维制成的廉价、水稳定的复合膜。该膜基于蛋白质的聚合物(蚕丝)表现出强大的机械和分离性能。同时,通过双溶剂法在MIL-101孔隙中自发聚合成聚多巴胺(PDA),将PDA固定在MOF内部表面,从而获得外部孔隙率。每克复合膜可结合高达30 mg的铀(U)和32 mg的As^(2+),能从1 mg/L的溶液中去除86%以上的Hg^(2+)离子,在几秒钟内即可达到可饮用的水平。这种广谱分离膜在废水处理、纳米技术、食品工业和生命科学等领域具有潜在的应用价值。

Contamination of drinking water by heavy metal ions and nuclear waste is a longstanding problem worldwide with serious public health consequences,and existing decontamination methods often fail to solve the problem quickly and economically.This paper reported an inexpensive,water-stable composite membrane made from hollow metal-organic frame(MOF)composites and silk nanofibers,a protein-based polymer(silk)that exhibited strong mechanical and separation properties.At the same time,polydopamine(PDA)was spontaneously polymerized in the pores of MIL-101 by double-solvent method,and the external porosity was obtained by fixing the PDA on the inner surface of the MOF.The composite membrane could bind up to 30 mg of U and 32 mg of As^(2+)per gram,and remove more than 86%of Hg^(2+)ions from a 1 mg/L solution,reaching potable levels in seconds.This kind of broad-spectrum filter membrane has potential applications in wastewater treatment,nanotechnology,food industry and life science.