Template-synthesized opal hydrogels

Opal hydrogels could be synthesized with polymer inverse opal template. A pH responsive opal N-isopropylacrylamide/acrylic acid copolymerized hydrogel was prepared as an example. The ordered structure and response to pH were investigated. Through the sol-gel process of tetrabutyl titanate, opal titania was obtained with the opal hydrogel template.