M. Mihit

Triazolic compounds as corrosion inhibitors for copper in hydrochloric acid

Purpose – To correlate the inhibitory effect of triazole compounds on the corrosion of copper in HCl at various temperatures by semi‐empirical molecular orbital theory.Design/methodology/approach – Two triazoles were selected as the best inhibitors among the triazole compounds tested. Gravimetric and electrochemical measurements were conducted.Findings – Correlation between inhibition efficiency and calculation of molecular orbital of triazole compounds was obtained. Cu(I)‐triazole complex formation was confirmed by UV spectroscopy.Research limitations/implications – The calculation of energetic levels of molecular orbital may be a tool to explain the classification of inhibitor efficiency.Practical implications – The theoretical calculation is a complementary mean to selecting an efficient inhibitor among a given series. Good agreement between the experimental methods explored and theoretical calculations was observed.Originality/value – The originality of this work was the finding of the correlation bet...

A study of tetrazoles derivatives as corrosion inhibitors of copper in nitric acid

Purpose – To evaluate the effect of some tetrazole compounds as corrosion inhibitors of copper in HNO3 at various temperatures.Design/methodology/approach – 1‐phenyl‐5‐mercapto‐1,2,3,4‐tetrazole (PMT) was selected as the best inhibitor among the tetrazole compounds tested. Gravimetric and electrochemical techniques were conducted.Findings – PMT was an excellent inhibitor for copper in acid. Its efficiency attained 97.5 per cent and decreased slightly with temperature.Research limitations/implications – The inhibition efficiency increased with the concentration of PMT to reach 97.5 per cent at 10−3 M. Good agreement between the various methods explored was observed. Polarisation measurements also showed that PMT acted as a mixed inhibitor.Practical implications – The efficiency of PMT increased with the concentration but decreased with rise of temperature in the 298‐333 K range. As such, PMT could be used in chemical cleaning and pickling processes.Originality/value – The originality of this work was the f...