Peer-Reviewed Journal Details
Mandatory Fields
Doyle, AM; Hodnett, BK
2006
July
Journal Of Non-Crystalline Solids
Adjusting the porous and structural properties of mesoporous silica by the addition of organic modifiers
Published
()
Optional Fields
porosity silica solution chemistry Zeolites SURFACTANT MESOPHASES ADSORPTION SOLVENT
352
21-22
2193
2197
The effects of the organic modifiers 2-cyanoethyltriethoxysilane and 3-aminopropyltriethoxysilane on the porous properties of silicates synthesised by co-condensation with tetraethyl orthosilicate were investigated. Materials were synthesised in aqueous solutions of cetyltrimethylammonium bromide or n-dodecylamine surfactants. Preparations using cetyltrimethylammonium. bromide and sodium hydroxide gave MCM-48, with an average pore diameter of 25 angstrom, while addition of 10 mol% (of total silica) 2-cyanoethyltriethoxysilane improved the mesoporosity characteristics; the modified preparation gave a more intense X-ray diffraction pattern confirming a more ordered structure with a greater volume of regular mesopores. Disordered materials with pores 145 A in diameter were formed using 2-cyanoethyltriethoxysilane modifier and ammonia as base. All preparations incorporating 3-aminopropyltriethoxysilane modifier were disordered and microporous. For silicates synthesised using n-dodecylamine surfactant, mesopores with diameter 118 angstrom were formed using 2-cyanoethyltriethoxysilane while preparations with 3-aminopropyltriethoxysilane and in the absence of a modifier were microporous. The particle sizes of the silicates displayed a clear correlation with the pore diameters: microporous silicates were 0.5-1 mu m in particle diameter, MCM-48 phase (25/27 angstrom) were 1-2 mu m, while relatively large mesoporous materials (> 100 angstrom) had particle dimensions 10-100 mu m. (c) 2006 Elsevier B.V. All rights reserved.
0022-3093
10.1016/j.jnoncrysol.2006.03.003
Grant Details