| Supramolecular hydrogels crosslinked by the weak non-covalent bond possess some special properties such as self-healing,shape memory and stimulus response,which made them have broad application in the fields of medicine,bioengineering,and energy.Photo-responsive supramolecular hydrogels have attracted much attention due to their characteristics of localized response,fast response speed and no pollution.Recently,photo-responsive hydrogels have developed with many new features,such as fluorescence,drug release and conductivity.In this paper,a series of photo-responsive supramolecular hydrogels crosslinked by the host-guest interactions are constructed,and the light-mediated host-guest interaction is used to regulate the ion conductivity of the hydrogel.The main contents are as follows:In chapter two,we design and synthesize a pure additive-free ion-conducting hydrogel possessing photo-switchable ionic conductivity.The hydrogel is crosslinked by the host-guest interaction via cyclodextrin and azobenzene group.Especially,adverse conductive behavior in one hydrogel can be achieved by simple ion exchange process.The light-controlled ionic conductivity of the hydrogels is emphatically studied.In hydrogel CD-AAzo Bipy Br,UV light promotes ionic conductivity from4.7×10-4 S×cm-1 to 6.1×10-4 S×cm-1due to the more flexibility caused by the dissociation between azobenzene and CD.However,UV light suppresses the conductive property in CD-AAzo Bipy TFSI hydrogel from 7.4×10-4 S×cm-1 to3.8×10-4 S×cm-1 because CD tends to form inclusion complexes with TFSI-and ionic mobility is decreased.In chapter three,a light-controlled conductive supramolecular hydrogel PAA-CD-Azo-TFSI,crosslinked by the host-guest interaction between azobenzene and CD,is constructed via free radical copolymerization with the complexes ofb-CD-AAm and BAzo,1-butyl-3-vinylimidazole bis(trifluoromethanesulfonyl)imide([VBIM]TFSI)and acrylic acid.UV light induces the isomerization of azobenzene with the dissociation of betweenb-CD and BAzo,and thenb-CD prefers to form a complex with TFSI-.As a result,the crosslinking point of the hydrogel has changed and the conductivity in the hydrogel reduces from 2.0×10-3 S×cm-1 to 1.4×10-3 S×cm-1due to the decreased ionic mobility. |
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