Experimental Investigation of Nickel Electrodeposits Brightness in the Presence of Surfactants: Modeling, Optimization and Polarization Studies

Nickel coatings were obtained from Watts bath conta ining sodium dodecyl sulfate (SDS) or polyvinylpyrrolidone (PVP) surfactants by direct current plating. The influence of electrolysis parameters, temperature, current density, concentration of surfactants and pH on the nickel deposits brightnes s is investigated through a multiple linear regression model with interaction. The model s obtained fitted very well the experimental data. ANOVA statistical analysis shows that all design factors are significant, and the brightness of nickel deposits obtained from bath containing PVP is more sensitive to the changes in the factors levels . The electrochemical behaviour of baths was discussed; the results revealed an inhibi tive effect exerted by both SDS and PVP. We have also found that the brightness and the in ibition are well linked and directly proportional. In addition, the corrosion r esistance of the nickel coatings was slightly improved, especially with PVP. Finally, th e optimization analysis showed that PVP could efficiently and eco-friendly substitute S DS as an additive of nickel electroplating.