The Preparation And Swelling Property Study Of A New Responsive Poly (Ionic Liquid) Hydrogel

Responsive hydrogels refer to those hydrogels which can be able to respond to external environmental stimuli,they have great potential application in biomedical field?industry and agriculture.Two kinds of ionic liquid were synthesized in this paper,and hydrogels were prepared by homopolymerization method with ionic liquid as monomers.We studied the swelling properties of these hydrogels.The details are as follows:(1)Two ionic liquids of EVImBr and HEVImCl were synthesized by the reference methods.The methods of silver nitrate titration,FT-IR and 1H NMR were used to characterized the structure of ionic liquids.Than used ionic liquids as monomers,N,N’-methylenebisacrylamide as cross-linker and azodiisobutyronitrile as initiator,introduced monomer cross-linking polymerization to prepare hydrogels.The structure of hydrogel was characterized by FT-IR and morphology by SEM.(2)The swelling properties test indicate that the swelling speed of those hydrogels was fast and they were ion-sensitive.The equilibrium swelling rate in saline solution was lower than in ultrapure water,at the concentration of 0-0.1 mol/1 saline solution the equilibrium swelling rate was decreased with the increasing ion concentration and it in CaCl2 solution was lower than NaCl solution,which indicated that ionic strength and ionic species affected the swelling properties contemporary.In the recycle system of ultrapure water-CaCl2 solution,the deswelling speed was very fast and reversible.The hydrogels was pH-sensitive,when the pH was lower or higher,the equilibrium swelling rate was decreased;when the pH was neutral,equilibrium swelling rate was the highest.The deswelling rate in acidic solution was a little fast than basic solution.