WALL-WATER INTERFACE - A MOLECULAR-DYNAMICS STUDY

This work was aimed at contrasting the properties of water near highly hydrophilic or highly hydrophobic walls. We performed molecular dynam ics computer simulations of two systems, both composed of a number of water molecules together with a layer of either purely hydrophilic or purely hydrophobic molecules restrained in mobility so as to form wall s. Simulations were done at constant temperature and at constant volum e or constant pressure. We found that the hydrophilic wall induces str ong ordering near its surface, but such order is present only up to ab out two molecular diameters away from it. On the other hand, the hydro phobic wall induces a slight ordering, but this ordering remains for s everal molecular diameters inside the bulk.