ISSN 2305-6894

2018, Vol. 7, Issue 1 (pp. 1-111)

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Investigating inhibitor influence on pickling tin metal resist from copper conductors of printed circuit boards

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D. Mendeleev University of Chemical Technology of Russia, Miusskaya sq. 9, 125047 Moscow, Russian Federation

Abstract: The inhibitor influence on nitric acid pickling printed circuit boards for removing the tin metal resist from copper conductors has been investigated. The proposed pickling solution has high selectivity in solving galvanic tin as compared to copper and it can be corrected easily.

Int. J. Corros. Scale Inhib., , 1, 1-8 PDF (1 264 K)
doi: 10.17675/2305-6894-2018-7-1-1

DLS study of a phosphonate induced gypsum scale inhibition mechanism using indifferent nanodispersions as the standards for light scattering intensity comparison

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1 PJSC “Fine Chemicals R&D Centre,” Krasnobogatyrskaya, 42, str.1, 107258 Moscow, Russian Federation
2 Mendeleev University of Chemical Technology of Russia; 125047, Miusskaya sq. 9, 125047 Moscow, Russian Federation

Abstract: The dynamic light scattering (DLS) special technique is used to study the bulk supersaturated gypsum aqueous solutions during the induction period in 0.2 mol·dm–3 NaCl at pH 9 and 25°C. It is based on the standard SiO2 nanoparticles (Ludox TM40) injection into the supersaturated gypsum solution. These nanoparticles act as an internal indifferent light scattering intensity reference and provide a semiquantitative measurement of a relative gypsum particles content in a blank solution and in the system treated with amino¬tris(methylenephosphonic acid), ATMP. It is found that ATMP sufficiently reduces the number of gypsum nuclei, spontaneously formed in the supersaturated solutions. In a parallel way the chemical forms of antiscalant in the experimental systems have been modeled. A tentative nonconventional mechanism of scale inhibition is proposed. It assumes that the active crystal formation centers already exist in any analytical grade aqueous solution in the form of solid nanoimpurities with a size ranging from one to several hundred nm. The ATMP antiscalant competes with Ca2+ and for these centers and blocks them. Therefore the number of gypsum growth centers diminishes significantly. Thus the concentration of corresponding CaSO4·2H2O particles gets reduced at least 10-fold. The collision rate of such particles decreases 100-fold. This explains both induction time prolongation by ATMP and sub-stoichiometry of its efficacy.

Int. J. Corros. Scale Inhib., , 1, 9-24 PDF (1 669 K)
doi: 10.17675/2305-6894-2018-7-1-2

Expired Podocip drug as potential corrosion inhibitor for carbon steel in acid chloride solution

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1 Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, India
2 Present Address: C-8, Ashokpuram, Dafi, Varanasi-221011, India
3 Center of Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

Abstract: The application of expired drugs as corrosion inhibitors provides a cost effective and environmentally benign alternative to otherwise tedious and costly disposal/degradation process. In this context, we have investigated the use of expired Podocip (PCIP) drug as corrosion inhibitor for carbon steel in 1 M HCl by weight loss and electrochemical methods. Polarization curves revealed that the inhibiting action of the PCIP is mixed-type. The adsorption of PCIP on carbon steel surface obeys the Langmuir isotherm. Impedance analysis showed that the presence of inhibitor considerably affects the charge transfer resistance and the double layer capacitance of carbon steel surface. SEM and AFM studies evidenced the formation of a protective film over metal surface.

Int. J. Corros. Scale Inhib., , 1, 25-37 PDF (1 400 K)
doi: 10.17675/2305-6894-2018-7-1-3

Corrosion studies of steel rebar samples in neutral sodium chloride solution also in the presence of a bio-based (green) inhibitor

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1 Faculty of Materials Science and Engineering, University of Miskolc, Hungary
2 Department of Surface Technology, Bay Zoltán Nonprofit Ltd. for Applied Research, Budapest, Hungary

Abstract: Steel rebar samples obtained from a steel mill operating in Hungary were investigated in several sets of laboratory experiments to reveal some of their corrosion properties in aqueous solutions containing sodium chloride salt. The effectiveness of an organic inhibitor extracted from a cheap organic waste of orange peel (so-called bio-based “green” inhibitor) was also studied. Results of the electrochemical polarisation measurements, as well as those of the direct corrosion weight-loss testing, showed the inhibition potential of the chosen new green inhibitor in stagnant neutral aqueous 3.5 wt% NaCl solutions in contact with air. It makes this bio-based inhibitor a promising candidate for using it as corrosion mitigating admixture in steel reinforced concrete.

Int. J. Corros. Scale Inhib., , 1, 38-47 PDF (1 405 K)
doi: 10.17675/2305-6894-2018-7-1-4

Pyrimidine derivatives as potential corrosion inhibitors for steel in acid medium – An overview

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1 Department of Chemistry, Shree Devi Institute of Technology, Kenjar, Mangalore, Karnataka, 574142 India
2 Department of Civil Engineering, Sri Dharmasthala Manjunatheshwara Institute of Technology, Ujire, Karnataka, 574240 India
3 Department of Chemistry, Sri Dharmasthala Manjunatheshwara Institute of Technology, Ujire, Karnataka, 574240 India

Abstract: Acidic environments are widely used in several industrial operations, such as oil well acidification, acid pickling, acid cleaning and acid descaling, which generally lead to serious metallic corrosion. Despite the relatively limited corrosion resistance of carbon steel, it is widely used in marine applications, chemical processing, petroleum production and refining, construction and metal-processing equipments due to its excellent mechanical properties and low cost. Out of several methods, usage of corrosion inhibitor is one of the most important techniques for controlling the corrosion. Several organic inhibitors have been tried for the corrosion inhibition of steel, out of which organic compounds with more than one hetero-atom containing pi-electrons are found to exhibit high inhibiting properties by providing electrons which interact with metal surface. However, the use of several heterocyclic inhibitors has caused negative effects on the environment because of their toxicity and non-biodegradability. In this context, pyrimidine derivatives are found to attract great interest due to their environmentally benign properties. In this article, it is aimed to review the usefulness of pyrimidine derivatives for the corrosion inhibition of steel in acid medium.

Int. J. Corros. Scale Inhib., , 1, 48-61 PDF (903 K)
doi: 10.17675/2305-6894-2018-7-1-5

Corrosion protection of steel by electropolymerization of o-chloroaniline and o-aminobenzoic acid in the presence of Tween 80 surfactant

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1 Faculty of Science, Chemistry Department, Alexandria University, P.O.Box 426, Alexandria 21321, Egypt
2 Pharos University, Faculty of Pharmacy, P.O.Box 3231, Alexandria, Egypt

Abstract: The conducting polymers, poly-o-chloroaniline and poly-o-aminobenzoic acid have been synthesized from their monomers on steel surface by cyclic voltammetry method in aqueous oxalic acid solution containing different concentrations of Tween 80 surfactant. The polymers were characterized by scanning electron microscope SEM. Potentiodynamic polarization and electrochemical impedance spectroscopy EIS techniques have been used to investigate the corrosion behavior of the polymer coated steel electrodes in 0.5 M H2SO4 solution. Effect of the surfactant on the electropolymerization process and the protection efficiency of the polymerized coat have been studied. Effect of substituent in the molecule of the monomer on the protection efficiency of the polymerized coat has been also studied.

Int. J. Corros. Scale Inhib., , 1, 62-77 PDF (2 368 K)
doi: 10.17675/2305-6894-2018-7-1-6

The protective properties of coatings on a magnesium alloy formed by plasma electrolytic oxidation in silicate electrolytes

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1 A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31, Moscow, 119071 Russian Federation
2 Institute of Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, pr. 100-letiya Vladivostoka 159, Vladivostok, 690022 Russian Federation
3 Far Eastern Federal University, Suhanova str. 8, Vladivostok, 690022 Russian Federation

Abstract: The protective properties and features of formation of plasma electrolytic coatings (PEO) on МА8 magnesium alloy in various silicate electrolytes were studied. It is shown that the addition of sodium fluoride to the silicate electrolyte reduces the number of pores in PEO coatings by increasing their size. PEO coatings formed in the electrolytes in the presence of fluorides possess greater protective properties both in the initial state and upon subsequent filling with corrosion inhibitors. A correlation between the stages of galvanostatic PEO machining and the corrosion resistance of the coatings was detected. The best coating characteristics are obtained at the stage of spark discharge and at the beginning of action of microarc discharges.

Int. J. Corros. Scale Inhib., , 1, 78-86 PDF (1 351 K)
doi: 10.17675/2305-6894-2018-7-1-7

Protection of low-carbon steel in solutions of mineral acids by nitrogen-containing pharmaceutical agents of triphenylmethane series

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1 A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation
2 Dmitry Mendeleev University of Chemical Technology of Russia, Miusskaya sq. 9, Moscow, 125047 Russia Federation
3 Bauman Moscow State Technical University (Kaluga Branch), Bazhenov str. 2, Kaluga, 248000 Russian Federation

Abstract: The corrosion of St3 steel in 2 M HCl, H2SO4 and H3PO4 in the presence of nitrogen-containing pharmaceutical agents of the triphenylmethane series, viz., fuchsine, Malachite Green and Brilliant Green, as well as Methyl Violet with related structure, has been studied. Of the compounds studied, the highest steel protection is provided by Brilliant Green, which in mixtures with urotropine or KNCS inhibits steel corrosion in HCl, H2SO4 and H3PO4 solutions at temperatures up to 95C. The high protective effect of the inhibitor formulations developed on the basis of Brilliant Green on steel corrosion in mineral acid solutions is a result of efficient inhibition of the electrode reactions on the metal by these compounds.

Int. J. Corros. Scale Inhib., , 1, 87-101 PDF (1 200 K)
doi: 10.17675/2305-6894-2018-7-1-8

Corrosion of steel in weakly acidic media at low H2S concentrations

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1 Derzhavin State University, ul. Internatsyonalnaya, 33, Tambov, 392000 Russian Federation
2 Tambov State Technical University, ul. Sovetskaya, 106, Tambov, 392000, Russian Federation
3 All-Russian Scientific Research Institute of Use of Machinery and Oil Products, Novo-Rubezhnyi per., 28, Tambov, 392022 Russian Federation

Abstract: The influence of low concentrations of H2S (25–200 mg/L) on the corrosion rate of St3 steel in model stratum water was studied by gravimetric, electrochemical methods and the linear polarization resistance method from ten-day experiments. In a simulated solution with pH = 6, an increase in the concentration of H2S in the range 25–100 mg/L causes an increase in the protective effect of H2S. At 200 mg/L H2S, the corrosion rate rises, but remains lower than in the solution without H2S. Introduction of an organic inhibitor to solutions containing H2S in these concentrations enhances the protective effect. Electron microscopy was used to characterize the state of the metal surface after corrosion. In a simulated solution with a lower pH (3.6), only 25 mg/L of H2S causes a decrease in the corrosion rate of the steel.

Int. J. Corros. Scale Inhib., , 1, 102-111 PDF (1 273 K)
doi: 10.17675/2305-6894-2018-7-1-9

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