A MONTE-CARLO STUDY OF BILAYER FORMATION IN A LATTICE MODEL

A Monte Carlo technique was applied to simulate a mixture of water wit h three-segment or with bolaform six-segment amphiphilic molecules in a coarse-grained lattice model. The molecular interactions between hyd rophobic and hydrophilic segments, and between hydrophobic segments an d water are purely repulsive; no additional attractive interactions ar e included. With a constant water content of 90% in both systems, we o btained the formation of layer structures at low temperatures and a sh arp phase transition to high-temperature phases. The heat capacity has a significant peak at the phase transition in both systems. Structura l and thermodynamic properties of the layers as a function of temperat ure were studied. Typical snapshots and statistically averaged density profiles illustrate the bilayer structure. (C) 1998 Elsevier Science S.A. All rights reserved.