Investigation of lipid + water systems. Part 4.—Proton magnetic resonance in an ordered lyotropic mesophase

P.m.r. measurements have been made on macroscopically-ordered samples of the smectic mesophase which occurs in the mono-octanoin + water system. The angular dependence of the doublet splittings obtained from both alkyl chain and hydroxyl protons indicate that there is a measurable degree of molecular ordering along a direction perpendicular to the lamellar planes of the mesophase. The degree of ordering of the alkyl chains is similar to that previously observed in magnetically-ordered nematic mesophases. The ordering of the water molecules is much smaller in magnitude and comparable to that previously observed in some hydrated silicates and fibrous materials.