Corrosion Durability Experimental Evaluation and Molecular Dynamics Simulation of Super-Hydrophobic Polypropylene/Graphene Oxide Nanocomposite Coating on Mild Steel Substrate

In order to prevent the penetration of corrosive agents into the mild steel substrate, a super-hydrophobic and anti-corrosion coating made of polypropylene (pp) was fabricated by the dip-coating method. additives such as pp grafted with maleic anhydride (pp-g-mah) and graphene oxide (go) were introduced to the coating to improve its super-hydrophobicity and corrosion durability. surface morphology, the distribution of go, and adhesion measurement were investigated by om, sem, raman, ftir spectroscopy, laser profilometer, and pull-off. the anti-corrosion properties of coatings were also studied over time by immersion, electrochemical impedance spectroscopy (eis), and potentiodynamic polarization. the results showed that the best corrosion durability after 30 days of immersion in the marine environment was related to the coating obtained from a solution contained 50 wt.% pp-g-mah and 0.1 wt.% go (pp/pp-g-mah/go-0.1) with a resistance (rct) of about 25 times greater than pure pp. this type of coating also indicated the best durability in terms of super-hydrophobicity after a week (reducing the water contact angle (wca) from 166◦ to 152◦). in addition, molecular dynamics (md) simulations were employed to confirm the development of essential parameters such as density, adhesion energy, contact angle, diffusion coefficient, solubility, and compactness by temperature incrementing due to the presence of go. the results illustrated that this additive behaved as an effective barrier against penetrating agents by increasing the adhesion (1.4 times) and wca (50◦), which owes to less surface energy (1.1 times) of the composite coating.

Corrosion durability experimental evaluation and molecular dynamics simulation of super-hydrophobic polypropylene/graphene oxide nanocomposite coating on mild steel substrate

In order to prevent the penetration of corrosive agents into the mild steel substrate, a super-hydrophobic and anti-corrosion coating made of polypropylene (PP) was fabricated by the dip-coating method. Additives such as PP grafted with maleic anhydride (PP-g-MAH) and graphene oxide (GO) were introduced to the coating to improve its super-hydrophobicity and corrosion durability. Surface morphology, the distribution of GO, and adhesion measurement were investigated by OM, SEM, Raman, FTIR spectroscopy, laser profilometer, and pull-off. The anti-corrosion properties of coatings were also studied over time by immersion, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization. The results showed that the best corrosion durability after 30 days of immersion in the marine environment was related to the coating obtained from a solution contained 50 wt.% PP-g-MAH and 0.1 wt.% GO (PP/PP-g-MAH/GO-0.1) with a resistance (Rct) of about 25 times greater than pure PP. This type of coating also indicated the best durability in terms of super-hydrophobicity after a week (reducing the water contact angle (WCA) from 166◦ to 152◦). In addition, molecular dynamics (MD) simulations were employed to confirm the development of essential parameters such as density, adhesion energy, contact angle, diffusion coefficient, solubility, and compactness by temperature incrementing due to the presence of GO. The results illustrated that this additive behaved as an effective barrier against penetrating agents by increasing the adhesion (1.4 times) and WCA (50◦), which owes to less surface energy (1.1 times) of the composite coating.