X-Ray Diffraction and NMR Studies on Mixtures of Non-Ionic Surfactant (C12EO2) and Phospholipids (POPC) |
| S.S. Funari Universität Leipzig, Fachbereich Physik, Linnéstraße 5, 04103 Leipzig, Germany C. di Vitta Institute of Chemistry, University of Sao Paulo, CP 26077, 05599-970 Sao Paulo SP, Brazil and G. Rapp European Molecular Biology Laboratory - EMBL, Outstation at DESY, Notkestraße 85, 22603 Hamburg, Germany |
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| We studied the temperature and concentration dependence of the POPC/C12EO2/water ternary system and identified and characterized the different phases occurring. The thermal behaviour is slightly dependent on the surfactant to lipid molar ratio Rs/l. At low surfactant content the behaviour is similar to the binary lipid/water system. Similarly at low lipid contents the system behaves similarly to the surfactant/water mixture. However, at molar ratios Rs/l between 2 and 3 a new hexagonal phase forms which is peculiar to the mixture. 2H NMR measurements indicated the existence of a lamellar phase containing also curved surfaces additional to the flat ones. The surface area per surfactant molecule was calculated to 0.23 nm2 which is in good agreement with the cross-section of a paraffinic chain. |
| DOI: 10.12693/APhysPolA.91.953 PACS numbers: 87.10.+e |