COMPARED ORGANIZATION OF THE MOLECULES OF NADEHP AND AOT - DETERMINATION OF THE MICROSCOPIC ORGANIZATION OF THE SODIUM BIS(2-ETHYLHEXYL)PHOSPHATE MOLECULE IN THE SOLID-STATE IN THE REVERSED HEXAGONAL LIQUID-CRYSTAL STATE

A method to determine the average shape of some molecules is described and applied to sodium bis(2-ethylhexyl)phosphate (NaDEHP) and sodium bis(2-ethylhexyl)sulfosuccinate (AOT). The volumes and lengths of the polar and apolar parts of these molecules are obtained from specific gravity measurements and from the lattice parameters of the hexagonal and lamellar liquid crystal structures. The shape of both molecules is described as a prism. The cross section of the elementary rod in the hexagonal structure intercepts respectively 2.5 and 6 molecules.