Reactivity of alkoxysilyl compounds: chemical surface modification of nano-porous alumina membrane using alkoxysilylazobenzenes

✍ Scribed by Kenji Kakiage; Masaki Yamamura; Erika Ido; Toru Kyomen; Masafumi Unno; Minoru Hanaya

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 213 KB
• Volume: 25
• Category: Article
• ISSN: 0268-2605
• DOI: 10.1002/aoc.1722

✦ Synopsis

Abstract

In order to clarify the chemical adsorption properties of alkoxysilyl compounds to metal‐oxide surface quantitatively and to obtain the information on the reaction conditions for the efficient surface modification, the chemical surface modifications of nano‐porous alumina membranes (NPAMs) by typical alkoxysilyl compounds of 4‐(triethoxysilyl)azobenzene, 4‐(diethoxyphenylsilyl)azobenzene, 4‐(ethoxydiphenylsilyl)azobenzene and 4‐(methoxydimethylsilyl)azobenzene were examined. The chemical surface modifications were performed by immersing NPAMs into the solutions of the alkoxysilylazobenzenes. Especially for 4‐(triethoxysilyl)azobenzene, the modification was investigated precisely by changing the solvent, temperature, concentration and water content of the solutions to reveal the effects of the reaction conditions on the adsorption property of alkoxysilyl compounds to metal oxides. The NPAMs having chemically modified surface were prepared successfully by the immersing method, and the alkoxysilylazobenzenes were confirmed to be bound on the NPAM surface through SiOAl bonds, which were indicated to be formed mainly by the direct condensation reaction between the alkoxysilyl groups of the azobenzenes and the hydroxy groups on the NPAM surface. The amounts of the azobenzenes adsorbed on the NPAM surface were estimated quantitatively by a visible absorption spectroscopy, and the results showed that the solutions with non‐polar solvents, higher temperatures and higher concentrations are suitable for the efficient surface modification. Copyright © 2010 John Wiley & Sons, Ltd.