| Autor: |
M., J. A. Garcia, Valverde, G., Zink, J. I. |
| Zdroj: |
Langmuir; May 2003, Vol. 19 Issue: 10 p4411-4414, 4p |
| Abstrakt: |
We report the use of organic additive carbazole as a structural modifier to change the mesophase of the mesostructured silicate cetyl trimethyl ammonium bromide (CTAB)-templated sol−gel thin films. The films were made by a dip-coating method on glass slides, which results in optical transparency. The films were characterized by X-ray diffraction patterns. For the small molar concentrations of carbazole (0.1−0.41) to CTAB, the films exhibit a two-dimensional hexagonal structure, which is also obtained for the films that do not have carbazole. As the molar concentration increases from 0.43 to 1.2, surprisingly the films acquire a lamellar structure with an extremely long-range order. This is an unusual result for the films prepared with CTAB, which always gives a hexagonal structure. We study the solvent effect to understand the cause of such a dramatic transformation in the films. |
| Databáze: |
Supplemental Index |
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