Preparation and characterization of pH and temperature dual responsive-, poly(n-isopropylacrylamide-co-itaconic acid) hydrogels using DMF and water as mixed solvents

Abstract

In this paper, pH and temperature dual responsive poly(N- isopropylacrylamide-co-itaconic acid) hydrogels were synthesized using DMF and water as mixed solvents. The surface morphologies and network structures of the newly synthesized hydrogels were characterized by scanning electron microscopy (SEM) and found gels prepared in the mixture exhibited porous structures. Temperature and pH sensitivities of the resultant hydrogels were examined through swelling ratios, deswelling/reswelling kinetics and deswelling- reswelling cycles experiments. The data obtained demonstrated that these hydrogels had improved pH and thermosensitive characteristics in terms of high equilibrium swelling ratio as well as excellent response dynamics upon external conditions due to changed chain conformations and their porous structures. © 2008 The Society of Polymer Science.