FORMATION OF POLYMER-METAL NANOSIZED COMP OSITES BY THE REDUCTION OF BIVALENT COPPER FROM ITS COMPLEXES WITH POLY(ETHYLENIMINE)

The pseudomatrix process of the reduction of bivalent copper by hydraz ine borane was studied in aqueous solutions of poly(ethylenimine). The reduction was accompanied by the formation of slowly or quickly cooli ng dispersions. The procedure for the evaluation of the phase composit ion after partial copper reduction was suggested. The most favorable c onditions to prepare stable (for 30 or more days) dispersions of coppe r particles with the diameter of 7-10 nm and narrow size distribution stabilized by a polymer were shown to be obtained in the solutions whe re the macromolecular complexing agent [poly(ethylenimine)] was comple tely saturated with Cu2+ ions. Such a situation was also possible when a small excess of free Cu2+ ions is present in a solution together wi th such a complex. In such dispersions, the size of copper particles i ncreased with time up to 20-50 nm. The particle growth can be stopped by the addition of another polymer [poly(N-vinylpyrrolidone)] to the d ispersion.