Water pipes corrosion inhibitors for Q235 steel in hydrochloric acid medium using spiropyrazoles derivatives

Abstract

Water pipes and drinking water quality deterioration in distribution systems and sea water desalination impose the use of corrosion inhibitors. The protective eect of spiropyrazole derivatives against Q235 steel and its adsorption performance were examined in solution of 1 M HCl utilizing TP (Tafel polarization), electrochemical frequency modulation (EFM), and electrochemical impedance spectroscopy (EIS) tests. The outcome data from hindrance eciency rise with the dose of inhibitor. The orders of %IE of spiropyrazole derivatives are given: (1) > (2) > (3). It was noted that the values of EHOMO and ELUMO dropping in order run parallel to the improvement in %IE, which support the preceding order. EIS spectra exhibited one capacitive loop and approve the protective ability. Molecular docking was utilized to get a full picture on the binding mode among spiropyrazoles derivatives and the receptor of 3tt8-hormone of crystal structure examination of Cu human insulin derivative. The morphology of protected Q235 steel was evaluated by checking electron magnifying instrument innovation with energy dispersive X-beam spectroscopy (SEM-EDX).