Deuteron nuclear magnetic resonance studies of phase equilibria in a lecithin-water system.
Water deuteron NMR spectra have been studied for the system dipalmitoyllecithin (DPL)-heavy water (D2O) at different compositions and temperatures. From an analysis of the spectra in terms of quadrupole splittings, a phase diagram has been constructed for the temperature range 25-60 degrees C and the composition range 4-15 mol of D2O/mol of DPL. Evidence is given that the "pretransition" observed by differential scanning calorimetry is caused by a crossing of a three-phase line. Strong support for a specific hydration of about 11 water molecules per lecithin molecule in the phase between the pretransition and main transition is also found.
D003903:Deuterium; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D011663:Pulmonary Surfactants; D014867:Water
D011663:Pulmonary Surfactants; D014867:Water; D003903:Deuterium