IN SITU FORMATION AND GROWTH OF COPPER AND NICKEL NANOPARTICLES IN POLYMER FILMS

摘要

Research into the preparation of nanocomposites containing metal nanoparticles dispersed in polymer matrices has been triggered by the technologically important applications of these nanocomposites in optics, sensors, and nanoelectronics. The major limitation of these nanocomposite materials is the difficulty of controlling their microstructure, e.g., size, size distribution, and interparticle spacing of the dispersed nanoparticles, during synthetic processes. A technique that allows precise control over composite microstructure is, therefore, indispensable for the preparation of composite materials with desired properties. Recently, in situ synthesis of these metal nanoparticle/polymer composites by the process of dissolution and reduction of metal salts/or complexes within polymeric precursors has been proposed. The advantage of this process is the uniform distribution of the metal source and the structural homogeneity of the precursors, which provides a resultant homogeneous dispersion of nanoparticles in polymer matrix. In this contribution, our recent development of fabrication of metal/polymer nancomposite thin films on glass substrate will be presented. We describe the use of ion-exchangeable, highly cross-linked polymer thin films as a matrix for the synthesis of nanocomposite thin films with embedded Cu and Ni nanoparticles. Using this method, we have successfully controlled the size of metal nanoparticles and thus optical and magnetic properties of the films by varying initial amount of doped metal ions and fabricated nanocomposite thin film patterns directly on glass substrates. The detailed investigation concerning the reduction behavior of metal ions and the changes in chemical structure of the matrix upon annealing will be also presented to provide insight into the appropriate mechanism of this process.