Dipron: an eco-friendly corrosion inhibitor for iron in HCl media in both micro and nano scale particle size - Comparative study.

This study was performed in order to investigate the ability of using sulfa drug (Dipron) with heterogeneous particle size in both micro and nano scale forms as an eco-friendlycorrosion inhibitor for iron (Fe) in hydrochloric acid solutions, in addition to decide which form would be more effective to inhibit Fe corrosion. The particle size analysis for micro and nano scale of Dipron was determined using BT-2001(Liquid) laser particle size analyzer and dynamic light scattering (DLS) respectively. Open circuit potential measurements, potentiodynamic and potentiostatic polarization techniques were performed at temperature range 20?60 ?C. The outcomes showed that inhibition took place by adsorption of the Dipron on Fe surface without altering the mechanism of corrosion process. The adsorption of Dipron on Fe surface was consistent with Langmuir?s adsorption isotherm. Physical adsorption mechanism was proposed from the calculated activation energy and thermodynamic parameters for the two forms of Dipron. The negative values of free energy of adsorption (〖∆G〗_ads^?) indicated that adsorption of Dipron followed a spontaneous process. The obtained results indicated that nano- scale of Dipron (NSD) has higher efficiency for corrosion inhibition than micro scale of Dipron (MSD). The inhibition efficiency increased with a corresponding increase in the inhibitor?s concentration and decreased with rise of temperature.