The T,x,p‐phase diagram of binary phospholipid mixtures

High pressure differential thermal analysis (DTA) has been applied to the study of the temperature‐composition‐pressure phase diagram of the binary saturated phospholipid mixtures dimyristoyl/palmitoyl phosphatidylcholine (DMPC/DPPC) and dimyristoyl/stearoyl phosphatidylcholine (DMPC/DPPC) in excess water. A temperature range from 10 to 100°C and a pressure range from ambient up to 1500 bar has been covered. The experimentally obtained phase equilibria of these binary systems are compared with thermodynamic calculations for ideal and non‐ideal mixing behaviour, and with recent results from Monte Carlo computer simulation studies, which not only permit determination of the phase diagram but also reveal a pictorial view of the local structure of the mixtures in the different parts of the phase diagrams.