Description:
<jats:p> Commercial plating baths may contain a large number of organic additives that play an important role in ensuring good-quality deposits. During electrodeposition process these compounds tend to wear out and degrade, so they must be frequently monitored and dosed to keep constant their concentration. Plating baths are complex matrices in which organic additives are present in minimal quantities compared to the other components, electrochemical methods, therefore, represent a reliable alternative to conventional chromatographic techniques because they allow quantitative analyses to be carried out considering the effects of additives on the electrodeposition rate regardless of their chemical composition and provide, at the same time, useful information about the condition of the bath. Methods based on the Cyclic Voltammetric Stripping (CVS) technique can be employed to quantify additives generally used in commercial acid copper plating baths. However, such procedures tend to be time and reagents-consuming and do not always provide accurate results. Electrochemical Impedance Spectroscopy (EIS) can represent a reliable alternative because it allows to achieve a detailed knowledge of the function of each additive and the interactions between them and to study the aging of plating baths [1]. EIS measurements were performed to quantify the three main additives present in commercial acid copper plating baths. These baths are widespread in different industrial sectors, such as fashion and electronic. The experiments were performed in three-electrodes cell, at 30 °C, by using a 10<jats:sup>5</jats:sup> – 10<jats:sup>-2</jats:sup> Hz frequency range. A large number of samples were investigated for a statistical treatment of the results that allowed us to find correlations between the concentration of each additive and some of the components of the equivalent circuit used to fit the data. The procedure applied to real samples provided promising results.</jats:p>
<jats:p>The authors acknowledge MUR and EU-FSE for financial support of the PhD fellowship PON Research and Innovation 2014-2020 (D.M 1061/2021) XXXVII Cycle in Chemical Sciences.</jats:p>
<jats:p> References</jats:p>
<jats:p>[1] Gabrielli, C. et al. Journal of Applied Electrochemistry <jats:bold>2008</jats:bold>, 38, 457-468, doi: 10.1007/s10800-007-9459-1 </jats:p>