Preparation and characterization of smart hydrogel nanocomposites sensitive to oxidation–reduction

Honeycomb-patterned hydrogel films sensitive to environmental oxidation–reduction supporting nanoparticle by adsorption were fabricated through the photopolymerization of ruthenium(4-vinyl-4′-methyl-2,2′-bipyridine)bis(2,2′-bipyridine)bis(hexaflurophosphate) and N-isopropylacrylamide. Nanoparticle adsorption by the hydrogel film was controlled by the dynamic changes in the surface morphology of the film in relation to environmental oxidation–reduction, which induces change of the oxidized and reduced states of ruthenium ion included in the hydrogel. For the adsorption of nanoparticles in the patterned hydrogel film, silver nanoparticles were immobilized in the hydrogel surface. Adsorptivity was obtained through measuring the released concentration of the silver nanoparticles using UV–vis spectroscopy in an aqueous solution. Desorption of Ag nanoparticles from the hydrogel surface was found to be larger in the oxidizing solution than in the reducing solution.