Azwain (Trachyspermum Copticum) Seed Extract as a Corrosion Inhibitor for Aluminum in Trichloroacetic acid

The present work investigates the corrosion of aluminum in Trichloroacetic acid containing leaves extract by mass loss measurement and electrochemical techniques. The inhibitor efficiency of Azwain (Trachyspermum Copticum) seed extract was found to very with concentration was kept uniform for 24 hours and temperatures was kept uniform for 2 hours. Experimental results revealed that inhibition efficiency (I.E %) increased with increasing inhibitor concentration. As temperatures increased, percentage of inhibition decreases. The value of free energy of adsorption (?G0ads), energy of activation (Ea), enthalpy of adsorption (?H0ads) and entropy of adsorption (?S0ads) were calculated. The result also showed that, adsorption of inhibitor molecules on the surface of aluminum followed Temkin, Freundlich and Langmuir adsorption isotherm model. Potentiodynamic study and Electrochemical Impedance Spectroscopy (EIS) implies that film developed on aluminum using the both of Trichloroacetic acid exhibits good corrosion resistance.