Composite Hydrogels: Robust Carriers for Catalytic Nanoparticles

A new type of composite hydrogel have been synthesized in which “nano‐tree” type polymer brush particles have been chemically entrapped in a poly(vinyl alcohol) (PVA) matrix by means of the disulfone reaction. This reaction leads to a chemical crosslinking of the nano‐tree brush particles within the PVA hydrogel. Obtained composite hydrogels can be successfully used as template for the deposition of Ag nanoparticles. Field‐emission scanning electron microscopy (FESEM) images demonstrate that monodisperse Ag nanoparticles (ca. 35 nm) are embedded into the composite hydrogel: Most of the silver nanoparticles were generated on the surface of the brush particles while a small amount of Ag nanoparticles was found to be entrapped within the PVA polymer network. We demonstrate that the resulting composite hydrogels can be used as a robust carrier for generation and immobilization of catalytically active Ag nanoparticles. The catalytic activity is investigated by monitoring the reduction of 4‐nitrophenol by NaBH4 in the presence of such a kind of composite hydrogel. The hybrid hydrogels can be easily reused many times as a catalyst and the catalytic activity can be retained over several months. magnified image