DSC STUDIES OF THE PHASE TRANSITION BEHAVIOR OF SYNTHETIC BILAYER MEMBRANES. PART I. BILAYER MEMBRANES OF DOUBLE-CHAIN AMPHIPHILES.

The gel-to-liquid crystal phase transition of bilayer membranes of synthetic double-chain amphiphiles was systematically examined by differential scanning calorimetry (DSC). A large amount of the DSC data - phase transition temperature (T//c), enthalpy change and entropy change - collected mostly in these laboratories were correlated with the structural element of the component amphiphiles. These amphiphiles are composed of alkyl tails, connectors, spacers, and hydrophilic heads. The T//c value is raised with increasing lengths of tails and spacers, and when hydrocarbon tails are replaced with perfluorocarbon tails.