Experimental and computational studies on the inhibition performances of benzimidazole and its derivatives for the corrosion of copper in nitric acid

I H Elshamy,Loutfy H Madkour

doi:10.1007/s40090-015-0070-8

I H Elshamy, Loutfy H Madkour

Open Access

https://doi.org/10.1007/s40090-015-0070-8

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Abstract

The inhibitive performance of seven synthesized 2-(2-benzimidazolyl)-4 (phenylazo) phenol (BPP_1–7) derivatives was investigated experimentally on the corrosion of copper in 2.0 M HNO3 acid using mass loss, thermometric and DC potentiodynamic polarization techniques. Quantum chemical calculations was investigated to correlate the electronic structure parameters of the investigated benzimidazole derivatives with their inhibition efficiencies (IE%) values. Global reactivity parameters such as E HOMO, E LUMO, the energy gap between E LUMO and E HOMO (ΔE), chemical hardness, softness, electronegativity, proton affinity, electrophilicity and nucleophilicity have been calculated and discussed. Molecular dynamics simulation was applied on the compounds, to optimize the equilibrium configurations of the molecules on the copper surface. The areas containing N atoms are most possible sites for bonding Cu (111) surface by donating electrons. Binding constant (K b), active sites (1/y), lateral interaction (f), equilibrium constant (K ads) and standard free energy of adsorption (∆G°) values obtained from either kinetic model and/or Frumkin adsorption isotherm were compared and discussed. Thermodynamic functions and activation parameters such as: E a, ΔH*, ΔS* and ΔG* at temperatures 303, 313, 323 and 333 K were determined and explained. IE% values of the examined compounds on Cu (111) surface followed the order arrangement: BPP_1 > BPP_2 > BPP_3 > BPP_4 > BPP_5 > BPP_6 > BPP_7. The theoretical data obtained as compatible with experimental results showed that the studied benzimidazole derivatives (BPP_1–7) are effective inhibitors for the corrosion of copper in nitric acid solution.

Highlights

Copper and its alloys are widely used materials for their excellent electrical and thermal conductivities in many applications such as electronics, production of wires, sheets, tubes and recently in the manufacture of integrated circuits [1]
Hard-soft acid and base (HSAB) [19] principle introduced by Pearson states that ‘‘hard acids prefer to coordinate to hard bases and soft acids prefer to coordinate to soft bases.’’ Polarizable chemical species is defined with soft concept
The inhibition efficiencies of seven benzimidazole (BPP_1–7) derivatives on the corrosion of copper were investigated by quantum chemical and molecular dynamics simulation studies

Summary

Introduction

Copper and its alloys are widely used materials for their excellent electrical and thermal conductivities in many applications such as electronics, production of wires, sheets, tubes and recently in the manufacture of integrated circuits [1]. BPP inhibitor molecules have the effect on the mechanism of dissolution of copper and cause activation of a part of the surface respect to the corrosive medium.

Results

Conclusion