A self-templated approach to TiO2 microcapsules

A self-templated approach has been developed for the synthesis of TiO2 microcapsules with tunable size and wall thickness by heating sol-gel derived TiO2 microspheres with poly(acrylic acid) (PAA) in a diethylene glycol (DEG) solution. PAA plays a crucial role in the formation of microcapsules by crosslinking the surface TiO2 nanoparticles and preventing them from dissolution by DEG. Hollow microcapsules form when DEG molecules penetrate the outer layer and remove the core materials by forming soluble titanium glycolate.