Assessment of Propylene Series Glycol Ethers and Their Derivatives as Potential Corrosion Inhibitors: Molecular Simulations

The present study focuses on evaluating the propylene series glycol ethers (PGE) and their derivatives for their corrosion inhibition potential. The corrosion inhibition efficiency was assessed through evaluation of their interaction with a highly electronegative iron surface (Fe(110)) using density functional theory (DFT) and molecular dynamics (MD) simulations. The simulation results infer that the PGE and Fe(110) interact via electron donor–acceptor phenomena where PGE would act as an electron donor. PGEs comprising amine (−NH₂), carboxylic acid (−COOH), and terminal hydroxy (−OH) functional groups possess strong electron-donating ability and therefore have potential to exhibit strong interaction with the electrophilic Fe(110) surface to form a protective coating. The PGEs were observed to adsorb on the Fe(110) surface mainly through the bridging ether group (R–O–R), with stronger adsorption observed when the inhibitor molecules adopt a horizontal orientation relative to the Fe(110) surface. Furthermore, the inhibitors significantly weakened the adsorption strength of corrosive Cl^– ions and H₂O molecules on the Fe(110) surface, thereby elucidating their inhibition activity.