Poly(ionic Liquid)-based Nanogels With Redox Response And Polymerization-induced Self-assembly

Molecular self-assembly is a“bottom-up” strategy to fabricate new functional materials.It has been considered as one of the most attractive and challenging scientific fields because of the complexity of the assembly process as well as the hierarchical structures of the resultant assemblies.As the second generation of the main molecule cyclodextrin,due to its own unique properties,it is widely concerned by scientists.Cyclodextrins can selectively form inclusion complexes with organic and inorganic molecules through non-covalent interactions.Because inclusion complex between host and guest is related with their matching degree,configuration and valence state of guest molecules,the association and dissociation of inclusion complex can be controlled by chemical induction,photo-irradiation,electrochemistry and so on.These host-guest complex systems have significant potential on designing and preparing stimuli-responsive functional materials and supramolecular nano-devices.Nano-sized materials such as nanospheres,fibers,and vesicles are currently drawing great attention for their potential applications in biomedicine,catalysts,food,analysis,testing and chemical industry.Poly(ionic liquid)s nanogel can self-assemble to form spheres,fibers vesicles or other morphologies.Some important parameters that influence the morphology of the particles formed by polymerization-induced self-assembly include the chemical nature of the polymer components,their interactions with each other and with the solvent,p H and salt concentration of aqueous solvent,monomer concentration and so on.Our previous research has found that a stable polyionic liquid-based nanogel can be prepared in one step by cross-linking and copolymerizing a quaternary phosphonium salt ionic liquid monomer and a cross-linking agent in a selective solvent,without adding any stabilizer.In this paper,ionic liquid monomers containing ferrocene were prepared and prepared,and a functionalized polyionic liquid nanogel was prepared in one step through the binary copolymerization with a cross-linking agent,and further investigation was conducted when β-cyclodextrin was used as the main molecule.The assembly of ionic liquid nanogels and its electrochemical activity enabled the realization of supramolecular self-assembly using polyionic liquid nanogels as building blocks.This thesis mainly contains three parts as following: 1.Preparation of ionic liquid monomers and functional compounds having different structures including:1-vinyl-3-[6-(ferrocenylcarbonyloxy)hexyl]imidazole(Fc6-Br IL),large Molecular chain transfer agents PILBu60/PILPh60 macro-CTA,4-vinylbenzyl triphenyl phosphonium chloride ionic liquid(PILPh),4-vinylbenzyl tributyl phosphonium chloride ionic liquid(PILBu),β-cyclodextrin(β-CD)dimers,and their structure and purity were determined by 1H NMR,13 C NMR,MS,and the like,and the melting point of the ionic liquid monomer was determined by DSC.2.One-step preparation of redox-responsive nanogels based on polyionic liquids and investigation of reversible self-assembly of oxidation-reduction based on β-CD and polyionic liquid nanogels.First,a stable nano-coagulation is achieved by cross-linking and copolymerization of a ferrocene-containing ionic liquid,a cross-linking agent,or an ionic liquid monomer containing ferrocene with a quaternary phosphonium salt ionic liquid monomer and a cross-linking agent in a selective solvent.Using UV-vis,FT-IR,DLS,SEM,CV and other methods to characterize the structure,morphology and properties of nanogels,the results show that by changing the ratio of ionic liquid monomer and crosslinker can be controlled by The particle size of the prepared nanogel,the novel nanogel has a reversible redox responsiveness.In addition,due to the introduction of ferrocene-containing ionic liquid monomers,the reversible assembly between nanogels and β-cyclodextrin dimers can be achieved by UV-vis,DLS,SEM,CV and other methods.3.The PILBu60/PILPh60 macro-CTA CLPN was synthesized through the reversible addition fragmentation chain transfer(RAFT)heterophasic polymerization-induced self-assembly.First,the macromolecular chain transfer agent PILBu60/PILPh60 macro-CTA was synthesized first,and then crosslinked with a cross-linking agent in a selective solvent to prepare a nanogel with a special morphology,using 1H NMR,FT-IR,DLS,SEM.The structure and morphology of the nanogels were characterized by the method.The results showed that the size of the prepared nanogels could be regulated by changing the ratio of PILBu60/PILPh60 macro-CTA and crosslinker.The polyionic liquid nanogels with controllable molecular weight and morphology were obtained.