Legodi, M. A.Murulana, L. C.Kirui, J. K.Nkuna, Anitah2018-06-052018-06-052018-05-18Nkuna, A. 2018. Investigation of anticorrosive properties of some ionic liquids on selected metals. . . http://hdl.handle.net/11602/1120http://hdl.handle.net/11602/1120MSc (Chemistry)Department of ChemistryThe corrosion potential of three ionic liquids (ILs) namely, 5-(Trifluoromethyl)dibenzothiophenium tetrafluoroborate (TDTB), 5-(Trifluoromethyl)dibenzothiophenium trifluoromethanesulfonate (TDTM) and 1-Ethyl-3-methylimidazolium ethyl sulfate [EMIM][ESO4] was studied for mild steel and zinc corrosion in 1.0 M hydrochloric acid using electrochemical, spectroscopic and gravimetric techniques. The studied ILs showed appreciable inhibition efficiencies at the considered concentration range. The highest inhibition efficiencies were observed at 30°C when inhibitor concentration was 8.0 × 10-2 M. The gravimetric data revealed that inhibition efficiencies decreased with an increase in temperature, the lowest inhibition efficiencies for mild steel and zinc were observed at 50°C. The potentiodynamic polarization results indicated that all three inhibitors are mixed-type inhibitors, with TDTM being a predominantly anodic inhibitor. The orders of inhibition efficiency at 8.0 × 10-2 M were TDTM > TDTB > [EMIM][ESO4] and TDTB > TDTM > [EMIM]ESO4] for mild steel and zinc, respectively. All inhibitors showed superior performance in mild steel than in zinc. The adsorption of the studied ILs on mild steel and zinc obeyed the Langmuir adsorption isotherm. The Gibbs free energy of adsorption (ΔG°ads) indicated that the adsorption process was spontaneous, and that corrosion inhibition occurred by a physical adsorption process. Surface morphology analysis through scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed a great improvement in the surface morphologies of mild steel and zinc specimens in the inhibited systems. The Fourier transform infrared spectroscopy studies confirmed the chemical interactions between the metal surface and the ILs. This is observed by means of the disappearance of characteristic absorption bands in the adsorption film FTIR spectra.1 online resource (xi, 115 leaves : illustrations (some color)enUniversity of VendaCorrosionUCTDAnticorrosive propertiesIonic liquidsTrifluoromethyl dibezothoophenium tetrafluoroborate (TDTB)541.372Ionic solutionsSurfaceIonizationIonsMetal ionsPhysicsDissertationNkuna A. Investigation of anticorrosive properties of some ionic liquids on selected metals. []. , 2018 [cited yyyy month dd]. Available from: http://hdl.handle.net/11602/1120Nkuna, A. (2018). <i>Investigation of anticorrosive properties of some ionic liquids on selected metals</i>. (). . Retrieved from http://hdl.handle.net/11602/1120Nkuna, Anitah. <i>"Investigation of anticorrosive properties of some ionic liquids on selected metals."</i> ., , 2018. http://hdl.handle.net/11602/1120TY - Dissertation AU - Nkuna, Anitah AB - The corrosion potential of three ionic liquids (ILs) namely, 5-(Trifluoromethyl)dibenzothiophenium tetrafluoroborate (TDTB), 5-(Trifluoromethyl)dibenzothiophenium trifluoromethanesulfonate (TDTM) and 1-Ethyl-3-methylimidazolium ethyl sulfate [EMIM][ESO4] was studied for mild steel and zinc corrosion in 1.0 M hydrochloric acid using electrochemical, spectroscopic and gravimetric techniques. The studied ILs showed appreciable inhibition efficiencies at the considered concentration range. The highest inhibition efficiencies were observed at 30°C when inhibitor concentration was 8.0 × 10-2 M. The gravimetric data revealed that inhibition efficiencies decreased with an increase in temperature, the lowest inhibition efficiencies for mild steel and zinc were observed at 50°C. The potentiodynamic polarization results indicated that all three inhibitors are mixed-type inhibitors, with TDTM being a predominantly anodic inhibitor. The orders of inhibition efficiency at 8.0 × 10-2 M were TDTM > TDTB > [EMIM][ESO4] and TDTB > TDTM > [EMIM]ESO4] for mild steel and zinc, respectively. All inhibitors showed superior performance in mild steel than in zinc. The adsorption of the studied ILs on mild steel and zinc obeyed the Langmuir adsorption isotherm. The Gibbs free energy of adsorption (ΔG°ads) indicated that the adsorption process was spontaneous, and that corrosion inhibition occurred by a physical adsorption process. Surface morphology analysis through scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) revealed a great improvement in the surface morphologies of mild steel and zinc specimens in the inhibited systems. The Fourier transform infrared spectroscopy studies confirmed the chemical interactions between the metal surface and the ILs. This is observed by means of the disappearance of characteristic absorption bands in the adsorption film FTIR spectra. DA - 2018-05-18 DB - ResearchSpace DP - Univen KW - Corrosion KW - Anticorrosive properties KW - Ionic liquids KW - Trifluoromethyl dibezothoophenium tetrafluoroborate (TDTB) LK - https://univendspace.univen.ac.za PY - 2018 T1 - Investigation of anticorrosive properties of some ionic liquids on selected metals TI - Investigation of anticorrosive properties of some ionic liquids on selected metals UR - http://hdl.handle.net/11602/1120 ER -