| 초록 |
Polyethylene oxide (PEO)-Titania (TiO2) organic-inorganic hybrid powder having different microstructures was synthesized and crystallized through a sol-gel process and subsequent heat treatments at elevated temperatures. As-precipitated hybrid powder showed two distinct morphologies one of which is spherical and the other is plate-like depending upon aging time. It is presumed that the structural variation was highly related with the formation of hydrogen bonds between a chelating agent (2, 4-pentanediol: AcAc) and a polymer component (polyethylene oxide: PEO). Also, microspherical particles with nano-crystalline anatase core / rutile shell structure were prepared through heat treatment at 800oC. The mechanism of core/shell structure formation was elucidated by the difference in thermal coefficient of expansion (TCE) of anatase and rutile crystals. In addition, the powder with plate-like structure showed retardation in anatase-rutile phase transformation kinetics compared to that with spherical structure. |
