CORROSION INHIBITION OF PYRROLIDONIUM IONIC LIQUIDS FOR MILD STEEL IN HC1 SOLUTION
Two kinds of ionic liquids,hydrogen sulfate and tetrafluoroborate of 1-octyl-2-pyrrolidonium ([Hnop]HSO_4/BF_4),were prepared.Their inhibition and adsorption behavior on mild steel in 1 mol/L hydrochloric acid solutions were investigated by mass loss and electrochemical methods,respectively.The results indicate the ionic liquids act as the mixed type inhibitors.The inhibition efficiency of ionic liquids increases with the increasing inhibitor concentration,decreases with increased temperature and reaches more than 90% for[Hnop]HSO_4 in 0.8 mmol/L at 303 K.The adsorption of[Hnop]HSO_4 on the surface of mild steel obeys the Langmuir adsorption isotherm via physicochemical adsorption,which is a spontaneous exothermic process.