Substituted benzotriazoles as inhibitors of copper corrosion in borate buffer solutions

This article provides an overview of works (2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015)(2016) devoted to the passivation of various metals and the influence of organic carboxylic acids and their salts thereon. The results of corrosion and electrochemical studies, as well studies on the composition and structural features of surface layers on the metals being protected by a variety of physicochemical methods are considered. Protection of metals by organic corrosion inhibitors (CIs) is based mostly on the adsorption of these compounds on a metal surface and subsequent formation of protective layers that minimizes access of corrosive ions to that surface. Adsorption can occur via electrostatic interaction of the CI with the metal substrate (physisorption), or it can involve charge sharing between the surface and CI (chemisorption), or combination of both interaction types can take place. Passivation of metals remains a central problem to be solved by the corrosion science. In the development of nanoindustry methods focused on creating ultrathin layers on metals capable of preventing the corrosion of the metals, an important role is played by surface passivation using CIs. Corrosion inhibitors can form passivating (often polymolecular) layers on metals but with thickness d < 10 nm, making them invisible to an unaided eye and keeping intact the decorative properties of a coated article's surface. This passivation can be done using volatile CIs from the vapor phase or nonvolatile CIs from aqueous solutions. Since metal passivation using conventional corrosion inhibitors of oxidizing type (e.g., nitrites, chromates) is seriously limited in practice due to environmental considerations, requirements for inhibiting formulations keep changing over time.The use of corrosion inhibitors in passivation has played a major role not only in the application of oxidants (chromates, nitrites, etc.) but also in adsorptive, often "oxideless" passivation that we discovered as early as in the mid-1970s [1]. As for corrosion inhibitors

mentioning

confidence: 99%

Organic corrosion inhibitors: where are we now? A review. Part II. Passivation and the role of chemical structure of carboxylates

Kuznetsov

2016

“…The technique described previously in [11] was used to determine Adsorption studies by the electrochemical impedance spectroscopy (EIS) method were carried out on an M1 copper electrode, which was mounted with epoxy resin into a polypropylene holder so that its working surface was the base of the cylinder (S Сu = 0.28 cm 2 ). The electrodes were polished with emery paper of different grades, up to P1000 paper, and then degreased with acetone.…”

Section: Methodsmentioning

confidence: 99%

“…The most widely used CI for copper is 1,2,3-benzotriazole (BTA), which has been known in this function since 1947 [3]. Extensive research and practical application of BTA, as well as other triazoles, have been repeatedly covered in the literature and is currently continuing [4][5][6][7][8][9][10][11][12][13][14]. Recently, however, CIs for copper belonging to the class of triazoles have been criticized because of their high toxicity.…”

Section: Introductionmentioning

confidence: 99%

Adsorption of 2-mercaptobenzthiazol on copper and MNZh-5-1 alloy and their protection from corrosion in aqueous solutions

2020

The adsorption, passivation and protective properties of 3-amino-1,2,4-triazole (3-AT) and 2mercaptobenzothiazole (2-MBT) on copper and MNZh 5-1 alloy were studied. The adsorption characteristics of both compounds on reduced and oxidized surfaces of copper and its alloy were calculated. On oxide-free surfaces (Е =-0.60 V) of both metals, physical adsorption of 3-AT and 2-MBT occurs, whereas chemical adsorption occurs on oxidized surfaces (Е = 0.0 V). The free energies of adsorption calculated by two independent methods, ellipsometry and electrochemical impedance spectroscopy, correlate well with each other. The orientation of the studied compounds on the metal surface was revealed by the ellipsometric method. 2-MBT on reduced and oxidized surfaces of the MNZh 5-1 alloy and copper is adsorbed in planar orientation, forming bonds with the surface through sulfur and nitrogen atoms. 3-AT on cathodically reduced surface of the alloy and copper is in planar orientation, whereas at the anodic potential, in a nearly vertical orientation. 2-MBT is adsorbed on oxidized copper better than 3-AT, apparently due to interaction with its oxide. It allows a protective coating to be formed on the surface that protects the metal well even at high chloride concentrations. Corrosion tests of copper and its alloy in 3.5% sodium chloride solution confirmed the high protective properties of 2-MBT. The created inhibitor mixture of 2-MBT with sodium laurate in equimolar ratio at a total concentration of 0.20 and 0.25 mmol/L allows one to achieve almost complete protection of copper and its alloy with Z = 99.1-99.3%, respectively.

“…The adsorption of NaC 13 from borate buffer with pH 7.4 on a copper electrode was studied by the reflective ellipsometry method (REM) in a specially designed cell that allows electrochemical and ellipsometric studies to be conducted simultaneously. The method and application of REM for studying the adsorption of organic compounds on copper are detailed in [18]. The ellipsometric experiment involved measuring the phase angle  and polarization angle  of light reflected from the electrode surface.…”

Section: Methodsmentioning

confidence: 99%

Adsorbtion of sodium tridecanoate on copper from aqueous solutions and copper protection from atmospheric corrosion

2018

The adsorption and protective effect of sodium tridecanoate CH₃(CH₂)₁₁COONa (NaC 13) on copper and the possibility of increasing the effectiveness of protection by joint use with a trialkoxysilane (TAS) were investigated. A set of electrochemical, ellipsometric and corrosion tests was carried out on samples of M1 copper (copper content > 99.9%). From an analysis of the anodic polarization curves of copper from solutions containing NaC 13 , it follows that when the inhibitor concentration is >0.07 mmol/l, the current density of copper active dissolution decreases and spontaneous passivation of the electrode occurs with a shift in the value of the pitting potential E pit in the positive direction. With an increase in the concentration of the inhibitor, the value of E pit increases while the anodic current density decreases. When the concentration of the inhibitor in the solution is 1.6 mmol/l or more, the value of E pit shifts to the oxygen evolution region. Studies of NaC 13 using the ellipsometric method showed that the adsorption of the inhibitor starts at very low concentrations, viz., 0.01 nmol/l. Adsorption is described by the Temkin equation with an adsorption free energy of 67 kJ/mol. In comparison with sodium oleyl sarcosinate СН 3 (СН 2) 7 СН=СН(СН 2) 7 СОN(CH 3)СН 2 СООNa (SOS) and sodium laurate CH3(CH2)10COONa (NaC 12), adsorption begins at lower concentrations. Sodium tridecanoate adsorption on copper is polymolecular. Accelerated corrosion tests with daily moisture condensation on copper pretreated with an inhibitor solution at 60°C for 5 minutes were carried out. It was shown a protective mixture of NaC 13 and TAS significantly increased the time until the appearance of the first corrosion site.