Molecular dynamics simulation of the early stages of the synthesis of periodic mesoporous silica

Miguel Jorge, Jose R. B. Gomes, M. Natalia D. S. Cordeiro, Nigel A. Seaton

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

We present results of detailed atomistic modeling of the early stages of the synthesis of periodic mesoporous silica using molecular dynamics. Our simulations lead to the proposal of a mechanism that validates several previous experimental and modeling studies and answers many controversial issues regarding the synthesis of mesoporous silicas. In particular, we show that anionic silicates interact very strongly with cationic surfactants and, significantly adsorb on the surface of micelles, displacing a fraction of previously bound bromide counterions. This induces an increase in micelle size and also enhances silica condensation at the micelle surface. The presence of larger silica aggregates in solution further promotes the growth of micelles and, by binding to surfactant molecules in different micelles, their aggregation. This work demonstrates the crucial role played by silica in influencing, by way of a cooperative templating mechanism, the structure of the eventual liquid-crystal phase, which in turn determines the structure of the porous material.

LanguageEnglish
Pages708-718
Number of pages11
JournalJournal of Physical Chemistry B
Volume113
Issue number3
Early online date31 Dec 2008
DOIs
Publication statusPublished - 22 Jan 2009

Fingerprint

Micelles
Silicon Dioxide
Molecular dynamics
micelles
Silica
molecular dynamics
silicon dioxide
Computer simulation
synthesis
simulation
surfactants
Silicates
Liquid Crystals
Cationic surfactants
porous materials
Bromides
Surface-Active Agents
Liquid crystals
Porous materials
proposals

Keywords

  • molecular dynamics simulation
  • early stages of synthesis
  • detailed atomistic modeling
  • periodic mesoporous silica

Cite this

Jorge, Miguel ; Gomes, Jose R. B. ; Cordeiro, M. Natalia D. S. ; Seaton, Nigel A. / Molecular dynamics simulation of the early stages of the synthesis of periodic mesoporous silica. In: Journal of Physical Chemistry B. 2009 ; Vol. 113, No. 3. pp. 708-718.
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abstract = "We present results of detailed atomistic modeling of the early stages of the synthesis of periodic mesoporous silica using molecular dynamics. Our simulations lead to the proposal of a mechanism that validates several previous experimental and modeling studies and answers many controversial issues regarding the synthesis of mesoporous silicas. In particular, we show that anionic silicates interact very strongly with cationic surfactants and, significantly adsorb on the surface of micelles, displacing a fraction of previously bound bromide counterions. This induces an increase in micelle size and also enhances silica condensation at the micelle surface. The presence of larger silica aggregates in solution further promotes the growth of micelles and, by binding to surfactant molecules in different micelles, their aggregation. This work demonstrates the crucial role played by silica in influencing, by way of a cooperative templating mechanism, the structure of the eventual liquid-crystal phase, which in turn determines the structure of the porous material.",
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Molecular dynamics simulation of the early stages of the synthesis of periodic mesoporous silica. / Jorge, Miguel; Gomes, Jose R. B.; Cordeiro, M. Natalia D. S.; Seaton, Nigel A.

In: Journal of Physical Chemistry B, Vol. 113, No. 3, 22.01.2009, p. 708-718.

Research output: Contribution to journalArticle

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