Inhibitive Effect of Benzotriazole on Copper Surfaces Studied by SECM

Abstract

The inhibitive effect of benzotriazole on a commercial copper surface ͑phosphorus-deoxidized copper͒ was studied by a scanning electrochemical microscope ͑SECM͒ in an aqueous sodium sulfate solution using ferrocenemethanol ͑FcMeOH͒ as the redox mediator. The formation of the inhibitive film was followed as a function of time and as a function of the potential of the copper substrate. The results were analyzed using the existing models in the literature. The results show that the potential has a crucial effect on the growth of the ͓Cu͑I͒-BTA͔ film. At a potential close to the dissolution range of copper, the surface changes gradually from almost ideally conductive to almost ideally insulating surface in the presence of benzotriazole, but at more negative potentials the effect is diminished and finally deceased. Quartz crystal microbalance experiments showed that the mass of an adsorbed layer must correspond to a multilayer.

Application of AC‐SECM in Corrosion Science: Local Visualisation of Inhibitor Films on Active Metals for Corrosion Protection

“…These layers introduce a physical barrier between the underlying metal and the electrolytic environment, and greatly hinder the investigation of such highly resistive systems. This is reflected in the scarcity of publications concerning the characterization of intact polymer coatings on metals [26][27][28] or for corrosion protection with inhibitors, [29][30][31][32] though both are topics of major interest in the corrosion sciences. Moreover, the possible transport of the added redox mediator through the surface layers into the polymer matrix and towards the metal/organic film interface cannot be neglected, at least for sufficiently long exposure times.…”

“…[46][47][48] The only antecedents for such studies employing microelectrochemical scanning techniques are the SECM-based investigations of benzotriazole films using zapproach curves on polarised copper by Mansikkamäki et al, [29][30][31] and on non-polarised copper samples using both z-approach curves and 3D topographic maps of the surface by Izquierdo et al [32] In those studies, however, ferrocene/ methanol had to be added to the test electrolyte to serve as freely diffusing redox mediator, though it might influence the corrosion process on the metal surface.…”

“…These organic molecules will modify the original conductive characteristics typical of the bare metal to varying degrees of insulating character depending on the extent of surface coverage and the barrier effects conferred on the metal/inhibitor system by these inhibiting layers. [29,32] In this way, the electrochemical activity and inhibiting properties of copper surfaces modified by triazoles can be investigated by 4D AC-SECM. The triazole compounds investigated were benzotriazole (BTAH) and 5-methyl-1H-benzotriazole (MBTAH).…”

Static secondary ion mass spectrometry investigation of corrosion inhibitor Irgamet ® 39 on copper surfaces treated in power transformer insulating oil

“…Benzotriazole (BTA) and its derivatives are among the most effective copper corrosion inhibitors [10,[21][22][23][24]. The protective film formed by BTA derivatives on copper surfaces may function both as a physical barrier to ionic or reactive species, and to attenuate copper dissolution [25]. Evidence of the presence of tolyltriazole on copper treated in oil was previously shown using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) [26,27], but contextual estimation of its thermal stability were never reported.…”

Kinetics of corrosion inhibition of benzotriazole to copper in 3.5% NaCl

“…Many factors affect the accuracy of measurements of the EQMB such as surface roughness, density, and viscosity of the liquid in contact with the crystal [41]. The EQMB has been used in studies of corrosion and protection of metals [13][14][15][42][43][44][45][46][47][48][49]. The objective of this paper is to analyze the kinetics of interaction of BTAH with the surface of copper in salt water.…”