The molecular structure of the interface between water and a hydrophobic substrate is liquid-vapor like Citation

The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. With molecular simulation for water and a tunable hydrophobic substrate, we apply the instantaneous interface construction [A.] to examine the similarity between a water-vapor interface and a water-hydrophobic surface interface. The intrinsic interface refers to molecular structure in terms of distances from the instantaneous interface. We show that attractive interactions between a hydrophobic surface and water a↵ect capillary wave fluctuations of the instantaneous liquid interface, but these attractive interactions have essentially no e↵ect on the intrinsic interface. Further, the intrinsic interface of liquid water and a hydrophobic substrate di↵ers little from that of water and its vapor.The same is not true, we show, for an interface between water and a hydrophilic substrate. In that case, strong directional substrate-water interactions disrupt the liquid-vapor-like interfacial hydrogen bonding network.