Microporous structure and enhanced hydrophobicity in methylated SiO2 for molecular separation

Share/Save/Bookmark

Castricum, Hessel L and Sah, Ashima and Mittelmeijer-Hazeleger, Marjo C. and Huiskes, Cindy and Elshof ten, Johan E. (2007) Microporous structure and enhanced hydrophobicity in methylated SiO2 for molecular separation. Journal of Materials Chemistry, 17 (16). pp. 1509-1517. ISSN 0959-9428

[img]PDF
Restricted to UT campus only
: Request a copy
273Kb
Abstract:Methylated microporous silica with high thermal stability and tuneable hydrophobicity was obtained by acid-catalysed sol–gel hydrolysis and condensation of mixtures of tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES). The gels exhibited a trend towards smaller ultramicropores with increasing methyl content, while in addition some supermicropores were formed with sizes of around 2 nm. For low MTES concentration, dilution prior to gelation and ageing resulted in materials with clearly smaller ultramicropores, whereas only a minor effect of dilution on structure was found at high MTES concentration. The small ultramicropore size in diluted materials can be associated with a higher extent of condensation of mainly TEOS monomers. Stable structures formed from MTES in an early stage of synthesis may explain the particular micropore structure of MTES-rich gels. With increasing methyl content and with dilution of the sol, the affinity of the surface to water was strongly decreased. The applicability of microporous silica in wet atmospheres may thus be improved by methylation, and their pore structure modified by adaptation of the recipe, which would be highly relevant for industrial gas and liquid separation by inorganic membranes.
Item Type:Article
Copyright:Royal Society of Chemistry
Faculty:
Science and Technology (TNW)
Research Group:
Link to this item:http://purl.utwente.nl/publications/59175
Official URL:http://dx.doi.org/10.1039/b610311a
Export this item as:BibTeX
EndNote
HTML Citation
Reference Manager

 

Repository Staff Only: item control page

Metis ID: 242613