Title: asdfghj

Biography:

Abstract

Use of inhibitors for the control of corrosion of metals is more accepted practice these days. For over 100 years chromium has been used as inhibitor but due to its toxic and carcinogenic nature its use is limited and banned now. So, Organic compounds with N, S and O are studied as alternative inhibitor and are found efficient as well. But these are also toxic and expensive. So, these days phytochemical compounds from plants products are studied to develop green corrosion inhibitor as they are environmentally friendly, less toxic, cheap and renewable.
Mahonia nepalensis extract in methanol was studied as corrosion inhibitor in 1M H2SO4 by electrochemical method (Potentiodynamic polarization), weight loss method, electrochemical impedance spectroscopy and scanning electron microscopic (SEM) imaging for mild steel. Corrosion efficiency of methanol extract in acid solution was found 94.91% for mild steel sample and it was 98.43% when extract was adsorbed on sample in acidic medium. Electrochemical method showed that the extract is mixed type inhibitor. Calculation from electrochemical method, electrochemical impedance spectroscopy and weight loss showed that the efficiency increases with increase in concentration. Efficiency varied from 95.2% (for 200ppm) to 98.43% (for 1000ppm) in electrochemical method , 89.20% (for 200 ppm) to 97.98% (for 1000 ppm) in electrochemical impedance spectroscopy and 89.83% (for 200ppm) to 95.12% (for 1000ppm) in weight loss method. In electrochemical impedance spectroscopy, increment in diameter of Nyquist plot indicates adsorption of inhibitor molecules on metal surface which inhibits the corrosion rate. Weight loss method showed that efficiency increases with increase in time and temperature. Efficiency varied from 93.01% in 3 hrs. to 94.66% in 24 hrs. for 1000 ppm solution and efficiency ranged from 92.93 % at 25°C to 97.08% at 45°C for 1000ppm solution in 6 hours and decreases after 45ºC. Decrease in efficiency with increase in temperature, the activation and free energies for the inhibition reactions support the mechanism of physical adsorption. In SEM image of surface of metal sample immersed in 1M H2SO4 for 24 hours, surface was highly porous with deep and large cracks but surface was relatively smooth by the formation of protective film on surface when immersed for same time after addition of inhibitor. The adsorption of extract on C-steel surface is consistent with the Langmuir adsorption isotherm.