| Abstract
| - The microrheology of cationic micellar solutions has been investigated as a function of added organic saltsusing quasielastic light scattering (QELS). Two organic salts, sodium p-toluene sulfonate and sodium salicylate,were used to induce microstructural changes in cetyl trimethylammonium bromide (CTAB) micelles. Themean-squared displacement (MSD) of polystyrene probe particles embedded in CTAB micellar solutionswas monitored by QELS in the single-scattering regime. Through the use of the generalized Stokes−Einsteinrelationship, the frequency-dependent complex shear moduli of each fluid were estimated from the Laplacetransform of the corresponding MSD. The salt-induced transition from nearly spherical to elongated wormlikemicelles and consequent changes in fluid response from viscous to viscoelastic are clearly captured bymicrorheology.
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