ممانعت کننده های خوردگی مس Copper Corrosion Inhibitors

Copper Corrosion Inhibitors

ممانعت کننده های خوردگی مس

ABSTRACT

Copper is metal that has a wide range of applications due to its good properties. It is used in electronics, for production of wires, sheets, tubes, and also to form alloys. Copper is resistant toward the influence of atmosphere and many chemicals, however, it is known that in aggressive media it is susceptible to corrosion. The use of copper corrosion inhibitors in such conditions is necessary since no protective passive layer can be expected. The possibility of the copper corrosion prevention has attracted many researchers so until now numerous possible inhibitors have been investigated. Amongst them there are inorganic inhibitors [1], but in much greater numbers there are organic compounds and their derivatives such as azoles [2-49], amines [50-56], amino acids [57, 58] and many others.

ممانعت از خوردگی مس در محلول H2SO4 اشباع از O2

Copper corrosion inhibition in O2-saturated H2SO4 solutions

ممانعت از خوردگی مس در محلول H₂SO₄ اشباع از O₂

ABSTRACT

Corrosion inhibition of copper in O2-saturated 0.50 M H2SO4 solutions by four selected amino acids, namely glycine (Gly), alanine (Ala), valine (Val), or tyrosine (Tyr), was studied using Tafel polarization, linear polarization, impedance, and electrochemical frequency modulation (EFM) at 30 C. Protection efficiencies of almost 98% and 91% were obtained with 50 mM Tyr and Gly, respectively. On the other hand, Ala and Val reached only about 75%. Corrosion rates determined by the Tafel extrapolation method were in good agreement with those obtained by EFM and an independent chemical (i.e., non-electrochemical) method. The chemical method of confirmation of the corrosion rates involved determination of the dissolved Cu2+, using ICP-AES (inductively coupled plasma atomic emission spectrometry) method of chemical analysis. Nyquist plots exhibited a high frequency depressed semicircle followed by a straight line portion (Warburg diffusion tail) in the low-frequency region. The impedance data were interpreted according to two suitable equivalent circuits. The kinetics of dissolved O2 reduction and hydrogen evolution reactions on copper surface were also studied in O2-saturated 0.50 M H2SO4 solutions using polarization measurements combined with the rotating disc electrode (RDE). The Koutecky–Levich plot indicated that the dissolved O2 reduction at the copper electrode was an apparent 4-electron process.

مطالعه ه­ای تئوری بر روی بازدارنده­ های خوردگی مس در اسید نیتریک

A theoretical study on the inhibition efficiencies of some quinoxalines as corrosion inhibitors of copper in nitric acid

مطالعه ه­ای تئوری بر روی بازده­ های بازدارندگی چند مورد از کوین­اگزالات­ ها به عنوان بازدارنده­ های خوردگی مس در اسید نیتریک

ABSTRACT

Quantum chemical calculations based on DFT method were performed on three quinoxalines compounds namely ethyl 2-(4-(2-ethoxy-2-oxoethyl)-2-p-tolylquinoxalin-1(4H)-yl)acetate (Q1), 1-[4-acetyl-2-(4-chlorophenyl)quinoxalin-1(4H)-yl]acetone (Q2) and 2-(4-methylphenyl)-1,4- dihydroquinoxaline (Q3), used as corrosion inhibitors for copper in nitric acid media to determine the relationship between the molecular structure of quinoxalines and inhibition efficiency. Quantum chemical parameters such as the highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital energy (ELUMO), energy gap (DE), dipole moment (l), electronegativity (v), electron affinity (A), global hardness (g), softness (r), ionization potential (I), the fraction of electrons transferred (DN), and the total energy (TE), were calculated. The theoretically obtained results were found to be consistent with the experimental data reported.

بازدارنده های جدید برای خوردگی مس

New inhibitors for copper corrosion

بازدارنده های جدید برای خوردگی مس

ABSTRACT

The study of the effectiveness of several potential copper corrosion inhibitors in acidic media was studied. The investigated thiazole derivative functional groups contain heterocyclic atoms such as nitrogen, sulfur, and oxygen. Thiazole derivatives, 5-benzylidene- 2,4-dioxotetrahydro-1,3-thiazole (BDT) 5-(4′-isopropylbenzylidene)-2,4-dioxotetrahydro- 1,3-thiazole (IPBDT), 5-(3′-thenylidene)-2,4-dioxotetrahydro-1,3-thiazole (TDT), and 5-(3′,4′-dimetoxybenzylidene)-2,4-dioxotetrahydro-1,3-thiazole (MBDT) were tested for copper corrosion inhibition properties. The electrolyte solution was 0.1 M Na2SO4. In situ information on corrosion and inhibition processes can be obtained using different techniques. Electrochemical measurements (EIS), in situ scanning probe microscopy (SPM), in addition to quartz crystal microbalance (QCM) measurements were applied. Those methods are very useful owing to their high sensitivity and resolution. Dynamic STM and AFM measurements on Cu(111) single-crystal electrode with and without the addition of some inhibitors were performed. The presence of the isopropyl group in the case of IPBDT produced far better protection against copper corrosion in acidic sulfate-containing media than the rest of the derivatives.