Synthesis of TiO_2 Nanoparticles Using Hydrogel as Template and TiO_2 Microspheres Using Microfluidic

Poly(acrylamide-co-acrylic acid) and polyethylene glycol/polyacrylic acid as templates and acrylic acid as an inhibitor were used to prepare TiO2 nanoparticles. Hydrogel with low speed of absorption and network structure suppressed the speed of hydrolysis of tetrabutyl titanate and growth rate of TiO2 nanoparticles. The as-prepared titanium dioxide nanoparticles have anatase phase structure with a narrow size distribution. As compared with poly(acrylamide-co-acrylic acid), polyethylene glycol/polyacrylic acid has lower expansion rate of water-absorption and higher stability of precursor solution. Using microfluidic process, precursor solution of polyethylene glycol/polyacrylic acid is chosen to prepare TiO2 microspheres. These as-prepared TiO2 microspheres have a uniform size distrubition and good sphericity, which crystal structure is anatase phase after calcination.