Theoretical Conclusions Based on the Polarographic Study of Organic Additives to Nickel Baths

摘要

Classical electroplating has been fundamentally changed by the use of brightening substances and other agents. As a result, high-performance baths have been developed that are suitable for the deposition of bright coatings and that operate at high current densities. In the case of some bright coatings, it has been found that the protective effect is less than that of coatings of equal thickness from classical baths. These unpleasant phenomena underscore the urgency of the thoroughest possible clarification of the most important theoretical relationships. For this reason intensive research and development has begun in this area. The purpose of the present study was to determine the effect of various organic additives on the polarographic curve of the nickel ion, with special consideration of the polarographic maximum of the first type, the shift in the reduction half-wave potential, the limiting diffusion current, and the value of the hydrogen overvoltage, and to compare the results with parallel Hull cell measurements taken during nickel electrodeposition. In this way a further contribution to the adsorption theory of brightners and levellers would be made. 11 refs., 7 figs., 3 tabs. (ERA citation 10:028232)