Molecular Dynamics Simulation of the Early Stages of the Synthesis of Periodic Mesoporous Silica

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Miguel Jorge (Autor) Outra; Jose R B Gomes (Autor) Outra; M Natalia D S Cordeiro (Autor) FCUP; Nigel A Seaton (Autor) Outra

Revista

Título: Journal of Physical Chemistry B

Vol. 113 Nº 3

Páginas: 708-718

ISSN: 1520-6106

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 37 Citações

ISI Web of Science

Scopus - 37 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Química

CORDIS: Ciências Tecnológicas > Engenharia > Engenharia química

Outras Informações

ID Authenticus: P-003-NR4

DOI: 10.1021/jp806686w

Abstract (EN): 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica