Synthesis of a novel environmentally friendly hybrid pigment for effective corrosion control of mild steel

This work aims to synthesize a novel environmentally friendly organic/inorganic hybrid pigment, based on sodium lignosulfonate and zinc acetate, to improve the anti-corrosion protection performance of the mild steel in 3.5 wt% NaCl solution. Open circuit potential, potentiodynamic polarization, and electrochemical impedance spectroscopy tests were employed to evaluate the anti-corrosion protection performance of the steel substrate after using the inhibitive pigment in saline solution. Moreover, scanning electron microscope equipped with energy dispersive spectroscopy, Fourier transform-infrared spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction patterns, and contact angle tests were used to evaluate the synthesized pigment's structure and inhibition mechanism. Based on the ICP-OES and UV-Vis results, the amount of the lignosulfonate molecules and Zn2+ cations releasing from the structure of the inhibitive pigments after 24 h immersion in saline solution is about 160 and 68 ppm, respectively. The electrochemical test results illustrated that the polarization resistance of the steel substrate improved from 4.53 k omega.cm2 to 22.5 k omega.cm2 after adding the inhibitive pigment to the saline solution. The production of the inhibitive film on the surface of the steel substrate is the main reason for this improvement.

Automated summary

This work aims to synthesize a novel environmentally friendly organic/inorganic hybrid pigment, based on sodium lignosulfonate and zinc acetate, to improve the anti-corrosion protection performance of mild steel in 3.5 wt% NaCl solution. Various tests were conducted to evaluate the performance of the inhibitive pigment and its structure. The results showed that the synthesized pigment effectively improved the corrosion resistance of the steel substrate in saline solution.