Abstract: The structure of phosphatidylethanolamine in Langmuir-Blodgett films and liposome in liquid crystalline state was investigated by means of the atomic force microscope(AFM), small angle X-ray scatting(SAXS) and 31P nuclear magnetism resonance( 31P NMR). By the atomic force microscope, some large and small lipid vesicles and a coexistent structure of cubic phase and bilayer phase of PE liposome were observed. The coexistent structure of the two phases is closely related to the structure of phospholipid, concentration, medium and pH. It was found that sodium salt solutes induce the formation of an Im3m(Q²²⁹) cubic phase in DEPE dispersions. The phase transition of DEPE with the change of temperature was investigated. The L_β→L_α transitions are at 37.5 ℃ and the L_α→H_Ⅱ transitions are at 63.5 ℃.

Key words: Atomic force microscope, Small angle X-ray scatting, Phosphatidylethanolamine, Cubic phase, Bilayer structure