Gold-Nanocluster-Doped Inorganic-Organic Hybrid Coatings on Polycarbonate and Isolation of Shaped Gold Microcrystals from the Coating Sol
详细信息 查看全文
- 作者：Goutam De and Debtosh Kundu
- 刊名：Chemistry of Materials
- 出版年：2001
- 出版时间：November 2001
- 年：2001
- 卷：13
- 期：11
- 页码：4239 - 4246
- 全文大小：228K
- 年卷期：v.13,no.11(November 2001)
- ISSN：1520-5002
文摘
Au-nanocluster-doped inorganic-organic hybrid coatings on polycarbonate substrates wereprepared for the application of abrasion-resistant colored coatings as well as nonlinear opticalmaterial. The Au-doped sol was prepared by incorporating HAuCl4·4H2O into a compositesol derived from 3-(glycidoxypropyl)trimethoxysilane, tetraethylorthosilicate, and 3-(methacryloxypropyl)trimethoxysilane via hydrolysis-condensation and epoxy polymerizationreactions. When the coated substrates were exposed under UV light, three reactions occurredsimultaneously: (i) reduction of Au ions into metallic Au nanoclusters, (ii) polymerizationof methacrylate groups, and (iii) strengthening of the silica network. As a result, the UV-cured coatings became reddish-purple and more abrasion-resistant than the polycarbonatesubstrate. UV-vis spectroscopy and TEM of the films showed a peak at 530 nm due to thesurface plasmon resonance of Au nanoclusters and the presence of 8-10 nm spherical Aunanoclusters, respectively. XRD of the films also showed the characteristic peaks of metallicAu nanoclusters. The inorganic-organic hybrid network at the sol stage also acted as anew breeding medium for the generation of shaped (triangular, hexagonal, prismatic, etc.)Au microcrystals from the Au-doped sol without UV irradiation. Electron diffraction suggeststhat these were single crystals with a preferential growth along the Au (111) plane.