The experimental acquisition of E M was accomplished by investigating the electrode polarization behaviors after subjecting the metallic substrate to a slow potential scan such that steady-state currents are obtained. Polarization experiments were performed to assess the effects of plating rates that fully describe the electroless bath. A complementary gravimetric determination of the electroless gold deposition rate was conducted in a circulating water bath using water-jacketed thermostated glass cells under identical conditions. This was used to assess the correlation of standard techniques with the plating rates obtained. The point of intersection of the anodic and cathodic curves yielded E M and i dep from which the deposition rate was calculated using Equation 2.
E D is on the order of several hundred mVs, depending on the pH and cyanide concentration.
Using the plating bath, other electrochemical experiments performed confirmed that increasing hydroxide concentration has two effects on DMAB concentration. First, it decreases oxidation potential with no net current flow, and secondly, it increases the rate of oxidation at any given potential. In the presence of 0.035M KCN, the DMAB polarization curve shifts approximately by nearly150 mV more positive. This results in a factor of two decrease in plating rate. Currently, we are investigating the influence of varying the concentration of these parameters on the overall plating efficiency.