| Autor: |
Lettow, J. S., Han, Y. J., Schmidt-Winkel, P., Yang, P., Zhao, D., Stucky, G. D., Ying, J. Y. |
| Zdroj: |
Langmuir; October 2000, Vol. 16 Issue: 22 p8291-8295, 5p |
| Abstrakt: |
We have investigated the phase transition between two distinct mesoporous silicas: SBA-15, comprising a hexagonally packed arrangement of cylindrical pores (6−12 nm in diameter), and mesocellular silica foams (MCF), consisting of spherical voids (22−42 nm in diameter) interconnected by windows of ~10 nm. Both SBA-15 and MCF are formed using an amphiphilic triblock copolymer (Pluronic P123) as a template. The synthesis conditions for the two materials are identical, except substantial trimethylbenzene is added to form MCF. We find that the phase transition occurs at an oil−polymer mass ratio of 0.2−0.3. Although the pore structures and pore sizes change dramatically, the mean surface curvature of the system remains essentially the same throughout the transition. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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