This content has been downloaded from IOPscience. Please scroll down to see the full text. Phase transitions in monolayers at air/water and oil/water interfaces Phase transitions in monolayers at aidwater and oil/water interfaces

Abstract. Real-space renormalisation group methods are used to study a two-dimensional lattice fluid model on a triangular lattice with application to phospholipid monolayers at airiwater and oiliwater interfaces. The phase diagram and pressure-area isotherms are calculated for various strengths of the couplings between neighbouring molecules. The choice of an overall attractive interaction energy between nearest-neighbours yields, in a certain temperature range, two phase transitions along the isotherms. These are interpreted to be a first-order vapour-liquid transition and a continuous transition between two types of liquid phase. With an overall repulsive interaction the first-order transition is absent. The nature of the continuous liquid-liquid transition is examined in detail