Layering of hydroxyl groups causes anisotropic molecular clustering in liquid ethanol on hydrophobic surfaces: A molecular dynamics study

Salting-out and Competitive Adsorption of Ethanol into Lipid Bilayer Membranes: Conflicting Effects of Salts on Ethanol–Membrane Interactions Studied by Molecular Dynamics Simulations

“…The permeated ethanol molecules were found to orient their hydroxyl groups toward the Lewis basic sites (Figure S10 in SI), which suggests that the permeated molecules were interacting with the sites directly or indirectly via other ethanol molecules. The deeper in the hydrophobic core, the more pronounced the orientation, possibly because of the lower ethanol levels, which can be explained by the tendency of interfacial ethanol molecules to preferentially form HBs perpendicularly in hydrophobic regions containing fewer hydroxyl groups. , On the other hand, our simulations also show that ethanol adsorption on the sites, membrane expansion, and ethanol permeation into the core occurred in this order (Figure S11 in the SI). The fact that the ethanol permeation occurs after the membrane disturbance suggests that the permeation is a result of ethanol–lipid interaction and membrane disturbance and supports the validity of evaluating the membrane permeability via ethanol permeation.…”