Humidity and temperature effects on CTAB-templated mesophase silicate films at the air-liquid interface
Off-specular X-ray reflectivity measurements were carried out to follow the in situ development of surfactant-templated silica thin films at the air-water interface under conditions of controlled relative humidity and temperature, using an enclosed sample cell designed for this purpose. The results...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1992. - 20(2004), 24 vom: 23. Nov., Seite 10679-84 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , |
| Format: | Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2004
|
| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Cetrimonium Compounds Membranes, Artificial Silicates Water 059QF0KO0R Cetrimonium Z7FF1XKL7A |
| Zusammenfassung: | Off-specular X-ray reflectivity measurements were carried out to follow the in situ development of surfactant-templated silica thin films at the air-water interface under conditions of controlled relative humidity and temperature, using an enclosed sample cell designed for this purpose. The results suggest a strong dependence of formation time and growth mechanism on ambient conditions. Thin films were synthesized at the air-water interface using cetyltrimethylammonium bromide (CTAB, 0.075 M) and a silica precursor, tetramethoxysilane (TMOS, 0.29-0.80 M) in an acidic medium. The studied humidity range was from 50 to 100%, the temperature was between 25 and 40 degrees C, and the TMOS/CTAB molar ratio was between 3.3 and 10.7. We observed that high humidity slows down the growth process due to lack of evaporation. However, increasing the temperature results in a decrease in the film-formation time. We proposed a formation mechanism for film growth as a consequence of phase separation, organic array assembly, and silica polymerization |
|---|---|
| Beschreibung: | Date Completed 24.04.2006 Date Revised 01.12.2018 published: Print Citation Status MEDLINE |
| ISSN: | 1520-5827 |