水凝胶模板制备纳米TiO_2及微流控合成TiO_2微球

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

以聚丙烯酰胺丙烯酸和聚乙二醇/聚丙烯酸两种水凝胶作为模板,丙烯酸做抑制剂合成纳米颗粒。水凝胶的缓慢吸水和网络结构,减缓了钛酸四丁酯的水解速率,并抑制TiO2的颗粒长大,制备出的TiO2纳米粉粒径分布窄,且为锐钛矿相结构。对比研究发现,聚乙二醇/聚丙烯酸水凝胶的吸水膨胀率更小,前驱体溶液的稳定性更高。选用聚乙二醇/聚丙烯酸前驱体溶液,采用微流控技术制备TiO2微球,制备出的微球具有球形度好、单分散的优点,焙烧后TiO2的晶体结构为锐钛矿。

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 tita- nium 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.