| As environmentally benign and "designer" solvents,ionic liquids(ILs)have attracted increasing attentions due to their extraordinary properties.Currently,ILs are not only considered as important alternative solvents,but also as materials with unique and tuneable properties which can be easily adjusted by suitable selection ofcomponent ion structures with a specific function.Parallel to the progress in IL studies as functional liquid materials,there has been growing attention to the development of the derivatives of ILs to accelerate their functionalization,such as the development of zwitterionic ionic liquids and poly(ionic liquid)s.The past ten years have witnessed a booming development in the research field of self-assembled aggregates based on ILs.Generally,ILs show isotropic properties because they form a liquid state at room temperature.If ILs are self-assembled into ordered states,they can be expected to show structure dependent properties derived from their self-assembled structures.Such investigation has deep significance to further extend the functionalization of both ILs and ordered self-assembled structures in diverse research fields.In this dissertation,zwitterionic ionic liquids and poly(ionic liquid)s with different structures and special functional groups were designed and synthesized,and the self-assembled aggregates based on these ILs were studied systematically.The outline and contents of this dissertation are as follows:1.In this chapter,a lithium-ion containing room-temperature ionic liquid([C12IPS][LiTFSI])was synthesized by mixing imidazolium-type zwitterions(3-(1-dodecyl-3-imidazolio)propanesulfonate,C12IPS)with lithium bis(trifluoromethanesulfonyl)imide.Nanostructured aqueous lithium-ion conductors having hexagonal,lamellar and bicontinuous cubic structures were constructed through self-assembly of this amphiphilic ionic liquid.Microstructures and phase behaviors of the obtained liquid crystals(LCs)were studied by POM,SAXS,and rheological measurement.These nanostructured lithium-ion conductors exhibited an assembled-structure dependent lithium-ion conduction behavior.The introduction of highly ordered and well-defined liquid crystal structures into room-temperature ionic liquid radically changes the conduction mechanism from diffusion to hopping.We expect this work may shed light on the potential of nanostructured aqueous lithium-ion conducting gel electrolytes in practical applications.2.In this chapter,a series of protic ionic liquids were synthesized by mixing amphiphilic imidazolium-type zwitterions(CnIPS,n=12,14,16)with sulfonic acids containing different substituent groups(CH3SO3H,C6H5SO3H,CF3SO3H).Nanostructured proton conductors having hexagonal and cubic structures were constructed by the self-assembly of these zwitterionic ionic liquids.These nanostructured proton conductors exhibited an assembled-structure dependent proton conduction behavior.The introduction of highly ordered liquid crystal structures efficiently improved protonic conductivity,suggesting the induction of proton conduction through a hopping mechanism.Temperature-responsive ionic conductivity behavior based on phase transition within the self-assembled liquid crystal structures was also observed.3.In this chapter,we presented a facile method to construct highly ordered and well-defined ionic channels in anion-exchange membranes(AEMs)through in-phase photopolymerization of liquid crystals(LCs).Hexagonal and lamellar LC samples were prepared by the self-organization of polymerizable amphiphilic imidazolium-based ionic liquids(3-Dodecyl-1-vinylimidazolium bromide,C12VIMBr).The preservation of LC nanostructures in the obtained polymeric membranes was confirmed by combination of SAXS,POM,and SEM measurements.Phase separations of LCs on the molecular level provided highly ordered and well-defined ionic channels for efficient anion conduction and meanwhile maintained a strong hydrophobic domain to suppress the swelling degree.After that,we present a facile method to construct polymerizable bicontinuous cubic phases through co-organization of amphiphilic C12VIMBr and p-xylene.AEM preserving bicontinuous cubic nanostructures was fabricated for the first time through in-phase photo-polymerization.The resulting membranes exhibit much higher hydroxide conductivity in comparison with control membranes without LC nanostructures,and also superior to the membranes preserving hexagonal or lamellar LC nanostructures.The membranes synthesized in this chapter provide a promising model system for understanding the idea of constructing ionic highways in AEMs through self-organization.4.Zwitterionic Soft Templates Synthesis of Noble Metal Nanostructues.In the first section,we have designed and synthesized two imidazolium-based zwitterions,3-((11-hydroxyundecyl)imidazolyl)propyl sulfonate(HIPS)and3-((1-dodecyl)imidazolyl)propyl sulfonate(DIPS).Equimolar mixture of HIPS and HAuCl4 forms multilamellar vesicles in aqueous solution without any additives.Triangular,hexagonal,and truncated triangular single-crystal gold nanoplates spontaneously generated at the vesicle bilayers were observed.Soft template synthesis of gold nanospheres was achieved via a stepwise reduction approach,ascorbic acid(AA)/HIPS equimolar mixture and NaBH4/HIPS equimolar mixture were used as reductant.In the second section,Zwitterionic wormlike micelles with AuCl4-,PtCl62-and PdCl42-counterions were fabricated through mixing equimolar3-(N,N-dimethylpalmitylammonio)propanesulfonate(PAPS)with HAuC14,H2PtCl6 and K2PdCl4,respectively.The transcript from wormlike micelles to Au,Pt and Pd wavy nanowire networks was achieved using a stepwise reduction approach.Ascorbic acid(AA)-PAPS and NaBH4-PAPS equimolar mixtures were used as reductants.Alloy nanowire networks with adjustable constituent ratio were also obtained using the mixed wormlike micelles as soft template.The results presented may provide inspirations and strategies for the fabrication of noble metal nanostructures with adjustable structure and constituent through soft templated attachment growth. |
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