1099-0739/asset/cover.gif?v=1&s=04bd9e08c0ca65d49547efbdbe335825939dd0de "Applied Organometallic Chemistry")
On leave from Korean Chemicals Company
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Materials, Nanoscience and Catalysis
Silica dissolution as a route to octaanionic silsesquioxanes
Article first published online: 15 MAY 2006
DOI: 10.1002/aoc.1071
Copyright © 2006 John Wiley & Sons, Ltd.
Additional Information
How to Cite
Kang, K. H. and Laine, R. M. (2006), Silica dissolution as a route to octaanionic silsesquioxanes. Applied Organometallic Chemistry, 20: 393–398. doi: 10.1002/aoc.1071
Publication History
- Issue published online: 7 JUN 2006
- Article first published online: 15 MAY 2006
- Manuscript Revised: 11 MAR 2006
- Manuscript Accepted: 11 MAR 2006
- Manuscript Received: 9 JAN 2006
Funded by
- USDA. Grant Number: 2005-00442
- Abstract
- References
- Cited By
Keywords:
- octaanionic silsesquioxanes;
- nano building blocks;
- silica dissolution;
- tetramethylammonium hydroxide
Graphical Abstract
Efforts to use Me4NCl/NaOH mixtures in place of Me4NOH gave very poor conversions to octaanion, OA, a low cost octahedral nanobuilding block. Kinetic studies show very low concentrations of Me4NCl in Me4NOH greatly inhibit OA formation perhaps through formation of a stable pentacoordinate surface species.
Abstract
The octaanion, [OSiO1.5]88− (OA) is a low cost, discrete nano silica particle that can be made directly from high surface area, amorphous silica reacted with Me4NOH in water alcohol mixtures. It would be ideal if Me4NOH could be formed in situ from, for example, Me4NCl and NaOH, as long known in the literature. This process would reduce costs and enable recycling of Me4NCl produced in the functionalization of OA with chlorosilanes, RMe2SiCl, to form [RMe2SiOSiO1.5]8 organic/inorganic hybrid nanobuilding blocks. Kinetic studies were conducted to assess base-promoted dissolution of fumed silica (25 m2/g) as a function of concentrations, times, etc., to form the octaanion [OSiO1.5]88− using Me4NOH, NaOH and mixtures of NaOH/Me4NCl. Surprisingly, we find that small amounts of Me4NCl greatly inhibit the dissolution reaction for reasons that are as yet unknown. Copyright © 2005 John Wiley & Sons, Ltd.