Photon Correlation Studies of Phase Transitions in Lipid Monolayers

Abstract

Monolayers of biologically important lipids spread at the air/ water interface are used as simple models for certain biomembranes. Study of these systems can yield information on the molecular interactions within their natural counterparts. Measurements of the temperature variation of the viscoelastic properties provide useful thermodynamic data on the molecular basis of monolayer structure. Phase transitions are of considerable importance in the biological milieu since many vital processes depend upon these phenomena. Photon correlation spectroscopy is a sensitive, non-perturbative technique for monitoring changes in monolayer visco-elasticity associated with thermotropic phase transitions. This technique has the advantage that it permits the simultaneous measurement of both static and dynamic monolayer properties.