高等学校化学研究 ›› 2002, Vol. 18 ›› Issue (1): 70-74.
Synthesis of Nanoscale Shell-core Titania Coated Silica Particles in the Presence of Polyether Polyamine and the Phase Transition
HUA Feng-jun1, SUN Jun2, HONG Ke2, GAO Lian1, YANG Yu-liang1
- 1. Key Laboratory of Molecular Engineering of Polymer, Fudan University, Shanghai 200433, P. R. China;
2. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Shanghai 200433, P. R. China
Synthesis of Nanoscale Shell-core Titania Coated Silica Particles in the Presence of Polyether Polyamine and the Phase Transition
HUA Feng-jun1, SUN Jun2, HONG Ke2, GAO Lian1, YANG Yu-liang1
- 1. Key Laboratory of Molecular Engineering of Polymer, Fudan University, Shanghai 200433, P. R. China;
2. State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Shanghai 200433, P. R. China
摘要： The nanoscale titania coated silica was prepared via a two-step precipitating approach, where the nanoscale silica nuclei were first prepared by passing an aqueous solution of sodium silicate through an ion-exchange resin bed, then coated with the precipitation from hydrolyzed butyl titanate in an ethanol-hexane mixture at a low pH value in the presence of poly(ethylene oxide) polyamine salt(PPA) at a high temperature of 90 ℃. In the second-step precipitating process, the spontaneously precipitated titania shell on the silica nuclei was stabilized in the suspension solution with the help of the adsorption of PPA on the particles. A possible precipitating mechanism was suggested. Furthermore, the amorphous titania shell could undergo crystallization from the amorphous to the anatase structure at a high temperature of 650 ℃, and a further phase transition from the anatase to the rutile structure in the different sintering processes at a rising temperature of 750 ℃.