Logistic Model of Ligand Selection for Chromium-Plating Electrolytes Based on Cr(III) Complexes

摘要

The effect of the ligand nature in chromium(III) complexes on chromium electrodeposition was studied.The predicting logistic model of ligand selection for chromium-plating electrolytes was constructed from experimental data.It was found that high-quality chromium coatings can be deposited from electrolytes of chromium(III) complexes with a ligand having the following acid-basic characteristics in the protonated form:pKt < 4.0 and 4.0 < sum_pK_n < 18.6.The proposed model was verified experimentally and used to prepare a chromium-plating electrolyte based on a chromium(III) malonate complex,which gives high-quality chromium coatings over a wide current density range.