Amphiphile diffusion in model membrane systems studied by pulsed NMR.
The translational diffusion of the amphiphilic molecules in a number of lyotropic liquid crystalline phases has been measured with the pulsed NMR pulsed magnetic field gradient method. The amphiphiles studied were soaps, monoglycerids and lecithins. Measurements were performed both for oriented lamellar and for cubic phases. The order of magnitude of the diffusion coefficients was found to be the same as in neat liquids of analogous compounds. It was also found that the difussion coefficient depend markedly on the amphiphile end group in a way that parallels the area per polar head group as determined in X-ray studies. When corrections for geometrical factors has been made the diffusion rate is approximately equal in cubic and lamellar phases containing the same amphiphile.
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004058:Diffusion; D009682:Magnetic Resonance Spectroscopy; D008566:Membranes; D008956:Models, Chemical