| Summary: | 碩士 === 長庚大學 === 化工與材料工程研究所 === 92 === Titanium Dioxide is an important one of nano-metarials, applied to photo-catalysis and cosmetics. There are ample of way to product titanium dioxide. In the study, we use supercritical carbon dioxide, to take place of organic solvent in methods of liquid synthesis, to arrive at clearer Green Process. By the way, SAS operating method is manipulated with the application of surfactant to produce titanium dioxide. It can combine many operating unit like reacting, drying and crystallizing in the supercritical fluids, thus, to avoid squandering the natural resources.
In the results, we cloud obtain about 5-10nm titanium dioxide particles, which would be agglomerating in the SCF system to second particles in sphere in range of submicron to micron meter. Analyses indicate that the size of primary is not sensitive by changing temperature and pressure, however, the size of second particle is susceptible to operating condition. And we find it would be in anatase form while a higher temperature or lower pressure term. Then, the study discusses the mechanisms of particle produced in supercritical carbon dioxide. We consider that amalgamating surfactant to system might to alter the ordinary mechanisms to vary the shape of particles.
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