Study the corrosion inhibition of carbon steel metal using pure curcumin in seawater solution

The corrosion inhibition of carbon steel in seawater solution (3.5%NaCl and DMSO) by pure curcumin has been studied at temperature range (298-328K) and different concentrations (2.7*10-6 ,1.3*10-5 ,2.7*10- 5 ,3.2*10-5M) using potentiostatic techniques. The results showed that the best corrosion inhibition efficiency was obtained with2.7*10-5Mpure curcumin concentration which reach to 77.5% at 298K.The corrosionrate increase with increase temperature at all purecurcuminconcentrations.Thecorrosion rate decreasewith purecurcuminconcentration increaseup to 2.7*10-5Mthen with increasing pure curcumin concentration than 2.7*10- 5M the corrosion ratewill be increase. Apparent activation energy, Arrhenius factor, free energyΔG* , enthalpy ΔH* and entropy ΔS* for corrosion processeswere calculated. The inhibition mechanism according to adsorption of pure curcumin molecules in the interface metal/solution and Langmuir adsorption isotherm type were applied.