Thermoresponsive hydrogels in the form of rods were prepared from N-isopropylacrylamide (NIPAM) and N-vinylimidazole (NIV) by a redox copolymerization method. Poly(NIPAM-co-NVI) hydrogels with different thermoresponsive properties were obtained by changing the initial NIPAM/NVI mole ratio and total monomer concentrations. Equilibrium swelling ratio, dynamic swelling ratio, and dynamic deswelling ratio were evaluated for all hydrogels systems. (C) 2003 Wiley Periodicals, Inc.