Determination of the Dissociation Rate of Dodecylpyridinium Iodide Micelles by a Temperature-Jump Technique^1a,b

Adsorption Relaxation for Nonionic Surfactants under Mixed Barrier-Diffusion and Micellization-Diffusion Control

“…[15], can be relatively easily applied to process experimental data and to verify whether in a given specific case the surfactant adsorption is influenced by the presence of a kinetic barrier. For example, recently we applied Eq.…”

“…One sees that for t → 0 the leading term of the time dependence in Eq. [15] is the linear term t/t a ; this indicates the presence of barrier control of adsorption at the short times. The typical diffusion term ∝ (t/t d ) 1/2 does not appear in Eq.…”

“…The typical diffusion term ∝ (t/t d ) 1/2 does not appear in Eq. [15]. In other words, the shorttime asymptotics is always controlled by the kinetic barrier to adsorption.…”

Fast Reactions in Micelles

“…On a time scale of 0 or smaller, we are dealing normally with thermal reactions [l]. However, on times of the region of 2 to 3, we are dealing with a breakup of micelles as would occur, for example, if the concentration of a micellar solution was suddenly decreased rapidly by a T jump technique [2]. On the time scale of 3 to 6 we are dealing with events such as exits of solutes from micelles and the exchanges of monomer units of the micelle from the solution into the micelle and vice cersa.…”

“…For a while there was substantial disagreement between the numbers quoted, for example by NMR measurements [lo] where exchange times of the order of microseconds were recorded, and other relaxation processes where times a g proaching fractions of seconds were often recorded [2]. This has been largely resolved [II, 121 and it is projected that the short time scale events in the -IO-'sec time domain CTAB, and non ionic micelles such as igepal.…”