Nuclear Magnetic Relaxation of 23Na in Different Phases in the Sodium Caprylate—Decanol—Water System

Abstract

Nuclear magnetic resonance line-widths of ²³Na have been determined at several compositions in two isotropic solution phases and five mesomorphous phases in the sodium caprylate-decanol-water system. The results obtained demonstrate that the rate of nuclear magnetic relaxation of ²³Na+ is primarily determined by the number of water molecules per sodium ion. this indicates that in all the phases investigated, the sodium ions are predominantly coupled to water molecules. A comparison with ⁸¹Br nuclear magnetic relaxation data shows that the bonding of sodium ions is markedly different from that of bromide ions in systems containing association colloids and water. This diversity is found to be due to differences in ion-water coupling.