EFFECTS OF CONFINEMENT ON THE PHASE-BEHAVIOR OF SUPERCOOLED WATER

Molecular dynamics simulations are performed to investigate phase beha vior of a thin film (thickness d similar to 2 nm) of supercooled water confined between two parallel planar walls. In contrast to bulk super cooled water, the confined water, under fixed normal pressures of 0.1 MPa and 500 MPa, does not exhibit the high density amorphous (HDA) to low density amorphous (LDA) liquid-liquid phase transition in the cour se of the cooling process. A possible explanation is that when the wat er is confined between two walls, the bulk HDA-LDA phase boundary and the associated critical point C' shift to lower temperature or/and low er P-zz (confinement pressure) as decreasing the film thickness. (C) 1 998 Elsevier Science B.V.