El Ibrahimi Brahim, Bazzi Lahcen, El Issami Souad
Applied Chemistry-Physic Team, Faculty of Sciences, University of Ibn Zohr P. O. Box 8106, Cité Dakhla Agadir Morocco
Industrial & Logistic Laboratory, Higher School of Management, Telecommunications and Computer Science, SUP MTI Rabat Morocco.
RSC Adv. 2020 Aug 11;10(50):29696-29704. doi: 10.1039/d0ra04333h. eCollection 2020 Aug 10.
Herein, the effect of a mediums' pH on the interfacial interactions between proline (Pro) amino acid and tin metal was studied. In this work, acidic and near-neutral pH values were considered. DFT-based calculations and Monte Carlo simulations were carried out in the aqueous phase to understand the role of pH in Pro/tin interactions. To confirm this role in terms of inhibition efficiency, the CC and AC electrochemical techniques were used. Based on the calculated parameters, it was outlined that the partially protonated Pro form exhibits significant affinity to interact with tin metal in near-neutral media. However, in acidic media, its affinity is decreased, whereas the full protonated form was found to be solvated in the solution and its interaction with the tin surface was not favorable. These findings indicated that the inhibition capability of Pro for tin could be better in near-neutral media than in acidic media. This expected behavior was confirmed experimentally, wherein an inhibition effectiveness of around 65% was obtained for Pro at pH 5, and 16% was observed at pH 2. Additionally, the results highlight the capability of employing computational studies to predict the prevention efficiency of anti-corrosion compounds by varying the solution pH.
在此，研究了介质的pH值对脯氨酸（Pro）氨基酸与锡金属之间界面相互作用的影响。在这项工作中，考虑了酸性和近中性pH值。在水相中进行了基于密度泛函理论（DFT）的计算和蒙特卡罗模拟，以了解pH在脯氨酸/锡相互作用中的作用。为了从缓蚀效率方面证实这一作用，使用了恒电流（CC）和交流（AC）电化学技术。基于计算得到的参数，概述了部分质子化的脯氨酸形式在近中性介质中表现出与锡金属相互作用的显著亲和力。然而，在酸性介质中，其亲和力降低，而完全质子化形式被发现溶解在溶液中，并且其与锡表面的相互作用不利。这些发现表明，脯氨酸对锡的缓蚀能力在近中性介质中比在酸性介质中更好。这一预期行为通过实验得到了证实，其中在pH为5时脯氨酸的缓蚀效率约为65%，在pH为2时观察到的缓蚀效率为16%。此外，结果突出了通过改变溶液pH值利用计算研究预测防腐化合物防护效率的能力。
