Electrochemical behavior for corrosion protection of mild steel (MS) in 1M HCl medium by using lidocaine drug as an inhibitor

Abstract

The impact of Lidocaine as a save corrosion inhibitor for mild steel (MS) in 1M HCl by using weight loss (WL), Hydrogen evaluation (HE), open circuit potential (EO C P), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and Electrochemical frequency modulation (EFM) techniques has been investigated. Weight loss studied at various temperatures between (25-45oC) but Hydrogen evaluation and electrochemical studies at room temperature. The effect of temperature on the inhibition of corrosion has been studied and the thermodynamic activation and adsorption parameters were calculated. The morphology of MS was examined by scanning electron microscope with energy dispersive X-ray spectroscopy (SEM-EDX) technology and atomic force microscopy (AFM). EIS data indicate that in the presence of drug the double layer capacitance was decreased and the charge transfer resistance increased. The adsorption of the Lidocaine on MS surface was found to obey Langmuir adsorption isotherm and elucidate the mechanism of corrosion inhibition. The Lidocaine drug acts as mixed type inhibitor. All surface examination confirms the formation thin film covered the surface of the metal and prevent the surface of the metal from corrosion.Lidokain, kao inhibitor korozije za zaštitu mekog čelik (MS) u 1M HCl, proučavan je ispitivanjem gubitka težine (VL), procene vodonika (HE), potencijala otvorenog kola (EOCP), potenciodinamičke polarizacije (PP), elektrohemijske impedansne spektroskopije (EIS) i elektrohemijske frekvencijske modulacije (EFM). Gubitak težine proučavan je na različitim temperaturama između (25 - 450C) a procena vodonika i elektrohemijska ispitivanja na sobnoj temperaturi. Proučavan je uticaj temperature na inhibiciju korozije i izračunati termodinamički parametri aktivacije. Mofologija MS ispitivana je pomoću skenirajućeg elektronskog mikroskopa sa tehnologijom disperzivne rentgenske spektroskopije (SEM - EDKS) i atomskom mikroskopijom (AFM). Tehnika elektrohemijske impedance je pokazala da prisustvo leka lidokaina u rastvoru smanjuje dvoslojni kapacitet i povećava otpor prenosa naelektrisanja. Utvrđeno je da adsorpcija lidokaina na površini Ms podleže izotermi Langmuir adsorpcije i razjašnjava mehanizam inhibicije korozije. Izračunati su parametri adsorpcije i utvrđeno je da lek lidokain deluje kao inhibitor mešovitog tipa. Sva površinska ispitivanja i analize potvrđuju formiranje tankog filma koji je prekrio površinu metala i sprečava koroziju površine metala.