ISSN 2305-6894

2018, Vol. 7, Issue 1 (in progress)

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

      • Yu.I. Kapustin, A.G. Kholodkova and T.A. Vagramyan
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., 2018, 1, no. 1, 1-8 (PDF 1264 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

      • K.I. Popov,1 M.S. Oshchepkov,1,2 N.A. Shabanova,2 Yu.M. Dikareva,1 V.E. Larchenko1 and E. Ya. Koltinova1
1PJSC “Fine Chemicals R&D Centre,” Krasnobogatyrskaya, 42, str.1, 107258 Moscow, Russian Federation
2Mendeleev 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 SO42- 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., 2018, 1, no. 1, 9-24 (PDF 1669 K)
doi: 10.17675/2305-6894-2018-7-1-2

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

      • P. Dohare,1 D.S. Chauhan1,2 and M.A. Quraishi3
1Department of Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, India
2Present Address: C-8, Ashokpuram, Dafi, Varanasi-221011, India
3Center 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., 2018, 1, no. 1, 25-37 (PDF 1400 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

      • A.S. Abbas,1 É. Fazakas2 and T.I. Török1
1Faculty of Materials Science and Engineering, University of Miskolc, Hungary
2Department of Surface Technology, Bay Zoltán Nonprofit Ltd. for Applied Research, Budapest, Hungary

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., 2018, 1, no. 1, 38-47 (PDF 1405 K)
doi: 10.17675/2305-6894-2018-7-1-4

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

      • K. Rasheeda,1,2 Vijaya D.P. Alva,1 P.A. Krishnaprasad2 and S. Samshuddin3
1Department of Chemistry, Shree Devi Institute of Technology, Kenjar, Mangalore, Karnataka, 574142 India
2Department of Civil Engineering, Sri Dharmasthala Manjunatheshwara Institute of Technology, Ujire, Karnataka, 574240 India
3Department of Chemistry, Sri Dharmasthala Manjunatheshwara Institute of Technology, Ujire, Karnataka, 574240 India

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., 2018, 1, no. 1, 48-61 (PDF 903 K)
doi: 10.17675/2305-6894-2018-7-1-5