Research Summary: The objective of this project is to evaluate the accuracy and study the range of applications of a new, non- contact electrochemical method for determining mass transfer boundary-layer thickness in natural and forced convection systems. The method, which will be applied to the electroplating and electro-dissolution of copper, converts concentration overpotentials after current interruption to a dimensionless concentration fraction. The experimental data is then matched to a theoretical electrode surface concentration decay model. Boundary-layer thicknesses are determined by equating the real time scale of the experimental data and the dimensionless time scale of the theoretical analysis. The advantages of the technique over other methods of determining boundary-layer thicknesses are: a) the technique can be applied to both electro-deposition and dissolution reactions over a wide range of applied currents, b) the method can be used to analyze convective mass transfer at irregularly shaped electrodes and c) the necessary experimental apparatus is simple and inexpensive. The proposed research regarding this new technique is as follows: a) theoretical and experimental boundary-layer analyses at a vertical flat plate copper anode and cathode with natural, forced and mixed natural/forced convection stirring, b) segmented copper anode and cathode boundary-layer experiments and c) boundary-layer thickness determinations in a semi-cylindrical cavity during plating and etching.
