Towards Robust and Uniform Assessment of Corrosion Inhibitor Efficiency

C. Ozkan1, L. Sahlmann2, C. Feiler2, M Zheludkevich2, P. Taheri1J.M.C. Mol1*

Department of Materials Science and Engineering, Delft University of Technology,

Mekelweg 2, 2628 CD Delft, The Netherlands

Institute of Surface Science, Helmholtz-Zentrum Hereon, Geesthacht, Germany

EXTENDED ABSTRACT: The use of chromates in corrosion protective coating technologies fbr structural aerospace applications is the subject of strict international health and safety regulations since many decades. High-throughput experimental setups and machine learning (ML) models show promise in discovering successor novel green inhibitors. However, a comprehensive quantitative electrochemical reference and standard fbr such approaches is still lacking. The literature often focuses on mechanistic explanations, and inhibitor performances are assessed with different electrochemical techniques at different times of exposure, different electrolytes and with different sample preparation procedures. This complicates combining and comparing the results from separate studies into one cohesive picture. In this study, various electrochemical techniques are used to illuminate and quantify the performance of potential inhibitors. The obtained experimental parameters can be employed directly as target parameter fbr training of a ML model that is predictive of the performance of untested compounds to create a shortlist of promising candidates. Moreover, the experimental investigation yields additional input features that can be combined with molecular descriptors derived from the molecular structure and atomistic simulations. These input features exhibit great potential to develop augmented quantitative structure­activity relationships as they allow to directly include information of the underlying mechanisms in training of the models. Keywords: corrosion inhibition; hexavalent chromium replacement; high-throughput screening; machine leamingReferences

Brief Introduction of Speaker
Aijan Mol

Aijan Mol is Professor Corrosion Technology and Electrochemistry and vice-chair of the Department of Materials Science and Engineering at Delft University of Technology, The Netherlands. Also, he is Scientific Director of the 4TU.High-Tech Materials Centre, embracing the materials research groups across the 4 technical universities in The Netherlands. The specific research fbcus areas of Aijan are: (i) local electrochemical analysis of corrosion mechanisms, (ii) surface treatment and interfacial bonding of organic coatings on metal (oxide) surfaces and (iii) multifunctional and eco-friendly corrosion inhibitors and evaluation of active protective and self-healing coatings. As from 2017, he is editor-in-chief of Elsevier's Corrosion Science, the globally leading journal in the research field of corrosion science, engineering and technology. Besides, in the period of 2014-2016 he was Chair of the Scientific and Technology Advisory Committee (STAC) of the European Corrosion Federation EFC. Hereafter he served EFC as Vice-President (2017- 2018) and President (2019-2020) and now is serving his term of Past President (2021-2022) of EFC. In August 2022, dining
EUROCORR2022 in Berlin, Aijan has received the EFC European Corrosion Medal for his impact and services to the global corrosion science and engineering community.
ACKNOWLEDGEMENT: VIPCOAT: H2020-NMBP-TO-IND-2020, Grant Agreement 952903.