Growth and Morphology Control of Silver Halide Nanoparticles in Templated Ag(I)-Coordinated Langmuir-Schaefer Films
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- 作者：Haofei Gong and Minghua Liu
- 刊名：Chemistry of Materials
- 出版年：2002
- 出版时间：December 2002
- 年：2002
- 卷：14
- 期：12
- 页码：4933 - 4938
- 全文大小：212K
- 年卷期：v.14,no.12(December 2002)
- ISSN：1520-5002
文摘
Growth and morphology control of silver halide nanoparticles in templated organizedmolecular films have been investigated. Instead of using conventional Langmuir-Blodgett(LB) films, in this paper silver (I) coordinated Langmuir-Schaefer (LS) films of coumarin 7(which have no long alkyl chains) were used. The nanoparticles and their aggregationpatterns were obtained in the film upon gas exposure and immersion in aqueous solutions.Because of the lack of long alkyl chains, the halide anion can easily penetrate into theAg(I)-coordinated LS films to form nanoparticles, and the formed silver halide nanoparticlescan be directly aggregated into various morphologies in the LS films. Upon exposing theAg(I)-containing coumarin 7 LS films to HCl or I2 gases, globular, cubic, dendrite, and nanorodmorphologies of the silver halide were observed. The formation and aggregation processesof the nanoparticles in the LS films were monitored at intervals. Different morphologieswere observed when immersing the Ag(I)-coordinated LS films into the aqueous solutionscontaining potassium halide. In the case of immersion into a KI solution, a nanowire of AgIwas obtained. We have found that globular nanoparticles were always formed in the initialaggregation stage. Different morphologies such as cubic, dendrite, nanorod, and nanowirewere obtained in subsequent reactions depending on the conditions. Directional aggregationwas suggested for the formation of these morphology patterns. The Ag(I)-coordinated LSfilm revealed itself to be a good template for the in situ generation of a nanosized silver (I)halide with different morphologies.