Differential scanning microcalorimetric study of sodium Di-n-dodecylphosphate vesicles in aqueous solution

Abstract

The scans recorded by differential scanning calorimetry are reported for aqueous solutions containing vesicles formed by sodium di-n-dodecylphosphate (DDP). The gel-to-liquid–crystal transition occurs near 35 °C, the melting temperature T_m. The dependences of heat capacity on temperature near T_m are analysed to yield related enthalpies of transition and patch numbers which record the number of DDP monomers which melt co-operatively. The dependences of the enthalpy of transition and patch number offer indications of vesicle size and the tightness of packing of monomers within the vesicles.