Probing inhibition effect of novel biopolymer based composite for the inhibition of P110 steel corrosion in 15% HCl under dynamic condition

The present work shows the chitosan composite development using Salicylaldehyde (Sali-Cht). The developed composite was used as P110 steel corrosion inhibitor in 15% HCl under dynamic condition at 1500 rpm using electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (EFM), and potentiodynamic polarization (PDP). The EIS results disclosed that Sali-Cht inhibits corrosion via charge transfer process. The PDP data indicated that Sali-Cht suppresses both the cathodic and anodic corrosion process. The maximum inhibition efficiency of Sali-Cht is 89.23% (400 mg/L). The adsorption of Sali-Cht over the steel surface was confirmed using X-ray photoelectron spectroscopy (XPS). Morphological changes on the steel surface were monitored by scanning electron microscopy (SEM). The thermodynamic parameters such as the adsorption equilibrium constant (K-ads) and the free energy of adsorption (delta G(ads)) were calculated and discussed. Several adsorption isotherms were tested and the experimental data fitted well with the Langmuir adsorption isotherm. Density functional theory (DFT) suggests that protonated forms of Sali-Cht have more adsorption ability than neutral forms. Molecular dynamic simulation (MD) study revealed that protonated form adsorbed flatly over the P110 steel surface, while neutral form adsorbed in a twisted manner.

Automated summary

This study investigates the use of chitosan composite developed with Salicylaldehyde as a corrosion inhibitor for P110 steel. The results show that the composite effectively inhibits corrosion via charge transfer process. The adsorption behavior and morphological changes of the composite on the steel surface are also analyzed.