The effect of nonylphenylpolyethylene glycol on the kinetics and morphology of silver cemented using zinc, iron, copper and aluminum

Abstract

The effect of nonylphenylpolyethylene glycol (D1) and cementing agents zinc, iron, copper and aluminum on silver cementation kinetics and deposit morphology was investigated. It was found that D1 inhibits both silver cementation and cementing agent dissolution with greater effect on cementing agent dissolution. The silver deposition rate and metal consumption per mole silver decreased in the order Zn, Fe, Cu, Al. The addition of D1 resulted in the rate of cementation decreasing to 77–90% of that when D1 was absent. The slower deposition resulted in more efficient consumption of cementing agent with 15–34% less dissolved when D1 was present. The deposit morphology strongly depends on the cementing agent: a coarse layer with high porosity was obtained on zinc, a fish-gill deposit morphology on iron, a compact fine deposit on copper and a patchy dendritic deposit on aluminum. D1 strikingly decreased the porosity of the deposits on zinc and iron.