MICELLE FORMATION IN SODIUM HEXADECYL SULFATE SURFACTANT SOLUTIONS STUDIED BY SMALL-ANGLE NEUTRON-SCATTERING

Micelle formation in aqueous sodium hexadecyl sulfate solutions is stu died by sma[I-angle neutron scattering. Measurements are carried out a t different concentrations (1.1, 2.2, 3.2, 5.4, 10.9 and 32.8 mM/dm3) and at different temperatures (40-degrees, 50-degrees, and 60-degrees- C). The monotonous evolution of interparticle correlation can be obser ved on the measured scattering patterns. At high concentrations (10.9 and 32.8 mM/dm3) scattering patterns are described by interacting elli psoids, but at low concentrations by non-interacting ellipsoids. Compu tation of the distance distribution function proved the ellipsoidal sh ape at 10.9 and 32.8 mM/dm3, but showed an unexpectedly large particle dimension and elongation of the micelles at lower concentrations.