Mechanistic Study of Silver Nanoparticle Formation on Conducting Polymer Surfaces
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- 作者：Nathan H. Mack ; James A. Bailey ; Stephen K. Doorn ; Chien-An Chen ; Han-Mou Gau ; Ping Xu ; Darrick J. Williams ; Elshan A. Akhadov ; Hsing-Lin Wang
- 刊名：Langmuir
- 出版年：2011
- 出版时间：April 19, 2011
- 年：2011
- 卷：27
- 期：8
- 页码：4979-4985
- 全文大小：953K
- 年卷期：v.27,no.8(April 19, 2011)
- ISSN：1520-5827
文摘
Conducting polymer (polyaniline) sheets are shown to be active substrates to promote the growth of nanostructured silver thin films with highly tunable morphologies. Using the spontaneous electroless deposition of silver, we show that a range of nanostructured metallic features can be controllably and reproducibly formed over large surface areas. The structural morphology of the resulting metal鈭抪olymer nanocomposite is demonstrated to be sensitive to experimental parameters such as ion concentration, temperature, and polymer processing and can range from densely packed oblate nanosheets to bulk crystalline metals. The deposition mechanisms are explained using a diffusion-limited aggregation (DLA) model to describe the semi-fractal-like growth of the metal nanostructures. We find these composite films to exhibit strong surface-enhanced Raman (SERS) activity, and the nanostructured features are optimized with respect to SERS activity using a self-assembled monolayer of mercapto-benzoic acid as a model Raman reporter. SERS enhancements are estimated to be on the order of 107. Through micro-Raman SERS mapping, these materials are shown to exhibit uniform SERS responses over macroscopic areas. These metal鈭抪olymer nanocomposites benefit from the underlying polymer鈥檚 processability to yield SERS-active materials of almost limitless shape and size and show significant promise for future SERS-based sensing and detection schemes.