The ordering behaviors of liquid under many-body dissipative particle dynamics potential at solid–liquid interface

This study utilizes many-body dissipative particle dynamics to analyze in detail the structural orderings of liquid density, stress, and other physical properties near solid–liquid (S-L) interfaces, examining their relationship with S-L and liquid–liquid (L-L) interaction potentials. By discerning the individual contributions from different phases to the overall force profile, our research reveals that the mutual influence between forces and density variations causes the wall’s impact to extend several multiples beyond the cutoff radius. Through a variety of scenarios involving different potentials, we demonstrate that the stratification period is a fundamental characteristic of the liquid phase, unaffected by the type of solid or the specific S-L interaction potential. Besides, the distance of the first liquid layer from the solid substrate is positively correlated with the position of zero potential (σ) of the S-L potential. Moreover, the oscillation amplitude of the density profiles does not necessarily increase monotonically with hydrophilicity, instead depends on the specific potential form and is a competing outcome of the two S-L potential parameters σ, and ε (the minimum potential energy). Therefore, for cases with the same wettability (e.g., the same liquid but different solids), the density ordering profiles may not completely align.