Fabrication And Performance Of Functional Membranes Based On Ionic Liquids

As a functional material,polymer functional thin films are widely used in selective permeation of substances,and have been used wildly as reaction sites,information transmission sites,and energy conversion sites.Ionic liquids(ILs)have a broad application prospect in many fields due to their superior properties,such as excellent thermal and chemical stability,obvious anti-microbial and anti-biofilm bioactivity.The research content of this paper is mainly based on the hydrophilicity and excellent antibacterial activity of ionic liquids,combined with "sulfur(Ⅵ)-fluoride exchange"(SuFEx)click reaction,layer-by-layer self-assembly technology,and electrospinning technology.The purpose of the research is to explore a simple and efficient method of constructing multi-functional polymer films,so as to provide a research foundation for material design involving ionic liquids.On the one hand,we have developed an efficient method to prepare polymer multilayers based on SuFEx click reaction.We first synthesized two kinds of polymers,which can be used in SuFEx click reaction mutual:poly-(N-vinyl-2-pyrrolidone)-copoly(3-(fluorosulfonyl)-propyl methacrylate)(PVP-co-PFPM),and tertbutyldimethylsilyl-modified polyvinyl alcohol(PVA-TBDMS).Then,by alternately coating PVP-co-PFPM and PVA-TBDMS solution layer by layer,covalently bonded polymer multilayer films were rapidly prepared by LbL technology with the occurrence of SuFEx click reaction between the two polymer chains.In addition,the surface of polymer multilayer films contains residual sulfonyl fluoride functional groups,which makes it possible to be functionalized through the SuFEx click reaction to graft functional groups such as ionic liquid to the outermost layer of the film.The experiments data demonstrate that the functional thin films prepared have potential application prospects in the field of bioengineering.On the other hand,self-assembly technology is not the only method to prepare functional polymer films.Based on the continuous electrospinning technology,we have developed a novel method to prepare multi-functional Janus polymer films.Firstly,the hydrophilic imidazolium ionic liquid monomer(IL-Br)was polymerized and crosslinked in situ in polyacrylonitrile(PAN)solution,and the hydrophilic layer of Janus film was obtained by electrospinning the solution.Then,the mixed solution of polyacrylonitrile(PAN)and polypentafluorostyrene(PPFS)was electrospun continuously on the hydrophilic layer film.Thus,a Janus polymer film with one side hydrophilic and the other side hydrophobic would be successfully prepared.The experimental results show that the film not only has the performance of oil-water separation but also has high bactericidal activity.These mentioned properties all indicate that the obtained multi-functional film has potential application prospects in daily life and various industry applications,such as sewage treatment.