Anticorrosion Efficiency of Inhibitor Coatings Based on Ammonium Cation with Different Substituents: The Influence of Wettability and Molecular Structure

Hanna Pianka,Sergei Mikhalyonok,Alexander Chernik,Abdelhafed Taleb,Vladimir Bezborodov,Sana Falah,Nina Kuz’Menok,Sandrine Zanna,Yanpeng Xue

doi:10.3390/coatings11121512

Abstract

In this work, different cationic surfactants with various aliphatic and aromatic ammonium cations were used to prepare inhibitor coatings and were characterized by different techniques such as IR spectroscopy and NMR. The inhibitor coatings were prepared by electrografting on the steel surface and their anticorrosion properties were evaluated in different media (HCl, H2SO4 and NaCl solutions). The electrochemical potentiodynamic polarization technique was used to study the inhibition efficiency of the prepared coatings. The dependence of the wetting properties of the electrografted layer and its homogeneity on the molecular structure of the prepared surfactants was studied. Particular attention was paid to the relationship between the properties of these surfactants in terms of critical micellar concentration, packing and wetting, and the anti-corrosion efficiency of their coatings. In this paper, we discuss the synergistic inhibition effect and the anticorrosion efficiency.

Highlights

Materials in their working conditions are usually subjected to different degradations, which induce loss of mass, alters their properties, and limits their sustainability and usefulness
From C1s core level spectra of bare and grafted steel electrode (Figure 4b), it can be observed that on the bare steel electrode, a weak signal was detected, whereas on the grafted steel electrode, there is the appearance of intense peaks corresponding to C1s core level and assigned to carbon of aliphatic and cyclic substituents (Figure 4b). These results indicate the existence of large number of carbon atoms on the surface of the steel electrodes, which confirms the success of the grafting process
Different cationic surfactants based on various aliphatic and aromatic ammonium cations were synthesised and used to prepare coatings, whose anticorrosive performance was evaluated for steel protection

Summary

Introduction

Materials in their working conditions are usually subjected to different degradations, which induce loss of mass, alters their properties, and limits their sustainability and usefulness. For metallic materials such as steel in aggressive media, additional degradation due to its electrochemical corrosion takes place, cations appear in the water and the corresponding negative charge is formed in the metal [1,2]. Electrons are released by the oxidation of iron in the anodic region and move through the metal structure to the cathodic region adjacent to the surface, where they react with oxygen and water to form hydroxyl ions according to the Reactions (2) and (3). The most common reduction reactions are the following: O2 (g) + 2H2 O(l) + 4e− → 4OH− (aq)

Methods

Results

Conclusion