SELF-DIFFUSION AND VISCOELASTICITY OF ELONGATED MICELLES FROM CETYLTRIMETHYL-AMMONIUM BROMIDE IN AQUEOUS SODIUM-SALICYLATE SOLUTION .2. TEMPERATURE EFFECT

Forced Rayleigh scattering and dynamic viscoelastic experiments are pe rformed to study slow global motions of networks formed by elongated m icelles from cetyltrimethylammonium bromide (CTAB) in aqueous sodium s alicylate (NaSal) solutions at six temperatures T from 25-degrees to 6 0-degrees-C. The CTAB concentration C(D) of the solutions is fixed at C(D) = 0.01 M and a ratio of salt concentration C(s) to C(D) is varied from 1 to 41. The self-diffusion coefficient D of the dye-labeled cet yldimethylamine incorporated in the micelles shows a complicated C(s)/ C(D) dependence with a maximum that is followed by a minimum at lower temperatures, but these two extremes gradually disappear with increasi ng T. The C(s)/C(D) dependencies of both the steady-state viscosity et a and the terminal relaxation time tau are found consistent with the d iffusion behavior. The D of all solutions tested monotonically increas es with T, but shows different functional dependence on T as C(s)/C(D) varies. The applicability of the theory of Brownian motion of a rigid rod in the semidilute regime is examined using D and tau values.