Open AccessTHE INHIBITION AND ADSORPTION PROPERTIES OF DTPMP TSC ON STAINLESS STEEL IN ACIDIC MEDIUM
Author(s) -
Pradeep Kumar
Publication year - 2017
Publication title -
journal of advances in chemistry
Language(s) - English
Resource type - Journals
ISSN - 2321-807X
DOI - 10.24297/jac.v6i1.6588
Subject(s) - adsorption , corrosion , dielectric spectroscopy , langmuir adsorption model , diethylenetriamine , materials science , enthalpy , methylene blue , fourier transform infrared spectroscopy , nuclear chemistry , polarization (electrochemistry) , physisorption , electrochemistry , inorganic chemistry , chemical engineering , chemistry , metallurgy , composite material , catalysis , organic chemistry , thermodynamics , physics , electrode , photocatalysis , engineering
The inhibition effect of diethylenetriamine penta(methylene phosphonic acid) (DTPMP) and Trisodium Citrate (TSC) on thecorrosion behavior of stainless steel in 0.5 M H2SO4 solution was investigated by using weight loss method. The combinedcorrosion inhibition efficiency offered 200 ppm of DTPMP and 150 ppm of TSC was 95%. Polarization study showed thatthe inhibitors inhibit stainless steel corrosion through mixed mode and electrochemical impedance spectroscopy (EIS)results confirm the adsorption of the inhibitors at stainless steel/acid interface. The adsorption of DTPMP and TSC ontothe stainless steel surface was found to follow Langmuir adsorption isotherm modes. Negative values of (ΔGads) in theacid media ensured the spontaneity of the adsorption process. The nature of the protective film formed on the metalsurface has been analyzed by FTIR spectra, SEM and AFM analysis. The activation energy (Ea), free energy change(ΔGads), enthalpy change (ΔHads) and entropy change (ΔSads) were calculated to understand the corrosion inhibitionmechanism.