Ternary Phase-Separation Investigation of Sol-Gel Derived Silica from Ethyl Silicate 40

Wang, Shengnan, Wang, David K., Smart, Simon and Diniz Da Costa, Joao C. (2015) Ternary Phase-Separation Investigation of Sol-Gel Derived Silica from Ethyl Silicate 40. Scientific Reports, 5 Art No.: 14560: . doi:10.1038/srep14560

Author Wang, Shengnan
Wang, David K.
Smart, Simon
Diniz Da Costa, Joao C.
Title Ternary Phase-Separation Investigation of Sol-Gel Derived Silica from Ethyl Silicate 40
Journal name Scientific Reports   Check publisher's open access policy
ISSN 2045-2322
Publication date 2015-09-28
Year available 2015
Sub-type Article (original research)
DOI 10.1038/srep14560
Open Access Status DOI
Volume 5
Issue Art No.: 14560
Total pages 11
Place of publication London, United Kingdom
Publisher Nature Publishing Group
Collection year 2016
Language eng
Formatted abstract
A ternary phase-separation investigation of the ethyl silicate 40 (ES40) sol-gel process was conducted using ethanol and water as the solvent and hydrolysing agent, respectively. This oligomeric silica precursor underwent various degrees of phase separation behaviour in solution during the sol-gel reactions as a function of temperature and H2O/Si ratios. The solution composition within the immiscible region of the ES40 phase-separated system shows that the hydrolysis and condensation reactions decreased with decreasing reaction temperature. A mesoporous structure was obtained at low temperature due to weak drying forces from slow solvent evaporation on one hand and formation of unreacted ES40 cages in the other, which reduced network shrinkage and produced larger pores. This was attributed to the concentration of the reactive sites around the phase-separated interface, which enhanced the condensation and crosslinking. Contrary to dense silica structures obtained from sol-gel reactions in the miscible region, higher microporosity was produced via a phase-separated sol-gel system by using high H2O/Si ratios. This tailoring process facilitated further condensation reactions and crosslinking of silica chains, which coupled with stiffening of the network, made it more resistant to compression and densification.
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2016 Collection
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 3 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 3 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 06 Oct 2015, 00:21:57 EST by System User on behalf of School of Chemical Engineering