The time influence on the protective ability of inhibitor film formed on the copper electrode surface in acidic media

Abstract

Using electrochemical impedance spectroscopy (EIS) the time infuence on the protective ability of inhibitor film formed on copper electrode were investigated in acidic sulphate solutions in presence of 5-benzylidene-2,4-dioxotetrahydro-1,3-thiazole (BDT), 5-(4-isopropyl-benzylidene)-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). The values of double layer capacitance (Cdl) and total resistance (Rp) were recording during the 24 hours in blank solution and solutions containing 1·10-5 mol/dm3 thiazole derivatives. On the basis of these data the time infulence on the protective ability of inhibitor film formed on copper surface were defined. Using obtained data the compactness of inhibitor film was calculated and it was found that it depends on chemical structure of investigated thiazole deivatives. IPBDT derivative only formed closely packed inhibitor film, which is able to protect copper surface during the time