| Autor: |
Takamitsu Tamura, Kyoko Aikawa, Masako Fujitsu, Katsumi Kaneko, Kazuo Ohbu |
| Rok vydání: |
1999 |
| Předmět: |
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| Zdroj: |
Colloids and Surfaces A: Physicochemical and Engineering Aspects. 150:95-104 |
| ISSN: |
0927-7757 |
| DOI: |
10.1016/s0927-7757(98)00718-3 |
| Popis: |
Mesoporous silica particles have been prepared by hydrolysis of TEOS (Si(OC2H5)4) in bicontinuous microemulsions containing polyoxyethylene (POE) dodecylether, isooctane and water. TEOS was dissolved in a continuous water phase and hydrolyzed by the dispersed water at around the phase inversion temperature (60°C). Undulating solid materials with layered mesostructures were produced from middle-phase microemulsions in the three phase region (o/w=0.2–0.7). On the other hand, the solids obtained from the lower aqueous phase in the three phase region were found to have a heterogeneous disordered structure. Measurements of the fractal dimensions were performed in the macropore region using a box-counting method for the outline of the SEM texture. We found that the macropore size distribution in the particles prepared from the middle-phase microemulsion follows the fractal rule with a dimension of 1.7. From the results of nitrogen adsorption/desorption curves on the silica, a steep increase in the adsorption amounts was observed at a relative pressure below 0.2, and adsorption/desorption hysteresis was also observed at a relative pressure between 0.3 and 0.5. These studies suggest that the silica synthesized in the bicontinuous microemulsion mesostructure has a very broad size range from micro to macropores with a fractal distribution. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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