Phase Transformations in Mesostructured Silica/Surfactant Composites. Mechanisms for Change and Applications to Materials Synthesis

Landry, Christopher C.; Tolbert, Sarah H.; Gallis, Karl W.; Monnier, Alain; Stucky, Galen D.; Norby, Poul; Hanson, Jonathan C.

doi:10.1021/cm000373z

Scientific article

English

Phase Transformations in Mesostructured Silica/Surfactant Composites. Mechanisms for Change and Applications to Materials Synthesis

Contributors

Landry, Christopher C.; Tolbert, Sarah H.; Gallis, Karl W.; Monnier, Alain; Stucky, Galen D.; Norby, Poul; Hanson, Jonathan C.

Published in

Chemistry of materials, vol. 13, no. 5, p. 1600-1608

Publication date

2001

Abstract

In this study, phase transformation of the hexagonal mesostructure MCM-41 to the cubic mesostructure MCM-48 is examined by in situ X-ray diffraction (XRD) of the transforming mesostructure and by XRD of products from bulk transformation experiments in Parr autoclaves. Transformations were studied under conditions of high pH and temperatures between 100 and 190 °C. Heating events took place after the hexagonal mesophase had assembled, but before it had fully polymerized. On the basis of these and previous results on transformations in silica−surfactant−water and surfactant−water systems, a model is proposed to explain the expected hexagonal → cubic transformation as well as the brief existence of a lamellar phase during the transformation. Additional experiments to establish synthetic parameters for the transformation included varying the silicon alkoxide source, replacing the supernatant prior to heating, and adding fluoride or aluminum to the reaction mixture. The results, taken together, illustrate the strong cooperativity between the organic and inorganic regions in controlling the assembly of the mesostructure and provide a better understanding of the effects that control phase transformations in these systems.

UNIGE affiliation entities

Faculté des sciences / Section de chimie et biochimie / Département de chimie physique

UNIGE research groups

Groupe Bill

Citation (ISO format)

LANDRY, Christopher C. et al. Phase Transformations in Mesostructured Silica/Surfactant Composites. Mechanisms for Change and Applications to Materials Synthesis. In: Chemistry of materials, 2001, vol. 13, n° 5, p. 1600–1608. doi: 10.1021/cm000373z

Article (Published version)

Identifiers

PID : unige:3217
DOI : 10.1021/cm000373z

Additional URL for this publication

http://pubs.acs.org:80/cgi-bin/sample.cgi/cmatex/2001/13/i05/pdf/cm000373z.pdf

Journal ISSN

0897-4756

598views

0downloads

Creation

21/09/2009 16:21:51

First validation

21/09/2009 16:21:51

Update

14/03/2023 15:23:14

Status update

14/03/2023 15:23:14

Last indexation

29/10/2024 12:12:47

Phase Transformations in Mesostructured Silica/Surfactant Composites. Mechanisms for Change and Applications to Materials Synthesis

Contributors

Published in

Publication date

Abstract

UNIGE affiliation entities

UNIGE research groups

Citation (ISO format)

Main files (1)

Identifiers

Additional URL for this publication

Journal ISSN

Technical informations

Creation

First validation

Update

Status update

Last indexation