Preparation of nanocrystalline copper by electrodeposition

Copper particles of sizes in the range 3.1 to 11.4 nm have been grown within gel compositions of the system CuO–SiO₂ by an electrodeposition process applying voltages varying from 5 to 15 V. Composite films of these metal particles dispersed in a polystyrene matrix have been prepared on Corning No. 7059 glass slides by a dip-coating technique and their optical absorption characteristics have been delineated. The spectra show maxima at wavelengths in the range 380 to 470 nm, depending on the particle size. The results have been analyzed using the Mie theory. The electrical conductivity as extracted from this analysis is found to have reasonable correspondence with data reported earlier for copper nanoparticles in glass-ceramic systems.