Corrosion inhibition of mild steel by schiff base compounds in various aqueous solutions: part 1

Lornoxicam & Tenoxicam Drugs as Green Corrosion Inhibitors for Carbon Steel in 1 M H2SO4Solution

“…41,42) It also revealed that the whole process was controlled by the surface reaction since the energy of the activation corrosion process in both the absence and presence of inhibitors was greater than −20 kJ mol −1 (43) ii) The positive sign of the enthalpy of activation (∆H * ) reflects the endothermic nature of carbon steel dissolution process meaning that dissolution of carbon steel is difficult. 44) Also all values of are larger than the analogous values of ∆H * indicating that the corrosion process must involve a gaseous reaction, simply the hydrogen evolution reaction, associated with a decrease in the total reaction volume 45) iii) The entropy of activation (∆S * ) in the absence and presence of inhibitor has large and negative values, this indicates that the activated complex in the rate determining step represents an association rather than dissociation, meaning that, a decrease in disordering takes place on going from reactants to the activated complex.…”

Quantum mechanical and electrochemical investigations on corrosion inhibition properties of novel heterocyclic Schiff bases

“…This will favour the adsorption of protonated Schiff base on the surface and hence reduce the dissolution of Fe to Fe 2+ 31 . Besides this electrostatic interaction between the protonated Schiff base and the metal surface, other possible interactions are i) interaction of unshared electron pairs in the molecule with the metal ii) interaction of π-electrons with the metal and iii) a combination of types (i-ii) [32][33][34] . If one examines the structures of Schiff bases, many potential sources of inhibitor-metal interaction can be recognized.…”

Electrochemical and AFM studies on adsorption behavior of a Polynuclear Schiff Base at carbon steel in HCl medium

“…This will favour the adsorption of protonated Schiff base (A9Y3PPA + ) on the surface 26 and hence reduce the dissolution of Fe to Fe 2+ (Fig.10). Besides this electrostatic interaction between the protonated Schiff base and the metal surface, other possible interactions are i) interaction of unshared electron pairs in the molecule with the metal ii) interaction of π-electrons with the metal and iii) a combination of types (i-ii) 27,28 . The π-electron cloud of the aromatic rings and the azomethine linkage also participate in the inhibition mechanism.…”