Effect of Poly(4-Vinyl Pyridine-Co-Methyl Methacrylate) on the Morphology of Electrodeposits of Zinc From Aqueous Solutions

Electrodeposition of Zn from zinc sulphate bath is affected by introduction of polyvinylpyridine copolymerized with methyl methacrylate into solution. The deposition process is strongly inhibited and new morphological features of the deposit are obtained. The latter were investigated by SEM. It was found that adsorption of the polymer on the substrate causes inhibition of nucleation so that 3D hemispherical bushy outgrowths, appear in small numbers, scattered over the surface. They are composed of very small flat crystallites clearly separated from each other. At increasing current density they are turning into fernlike dendrites. Other interesting shapes are also found. Experimental conditions leading to the observed morphology are presented.--AA