Probe diffusion in the presence of nonionic amphiphiles: Triton X 100

Aggregation Behavior of Nonionic Surfactants Synperonic A7 and A50 in Aqueous Solution

“…Phillies et al (7,8) studied the same system and found that Triton X-100 micelles are adequately represented as hard spheres. We recently reexamined Triton X-100 solutions by dynamic light scattering and by fluorescence quenching experiments, but at lower concentrations, 2-6 g/L.…”

“…[8] where [probe] sat is the saturated probe concentration in the micellar (m) and water (w) phases, respectively, C sur (g/L) is the surfactant concentration, and K is the equilibrium constant. Partitioning can also be described by the partition coefficient K v that takes into account the quantities of the probe in the micellar and water phases relative to the phase volumes, [9] whereM is the mean molecular weight of the surfactant (444 for A7, 2540 for A50) and v R is the molar volume of the hydrophobe.…”

“…In view of the importance of these materials, a significant number of studies over the past 20 years have investigated the self-association of a variety of nonionic surfactants. Many of the studies focused on the aggregation behavior, microstructure, and physicochemical properties of the micelles formed in relatively dilute solution (3)(4)(5), whereas other experiments examined the periodic structures formed by these surfactants at high concentrations (6)(7)(8). A variety of physical techniques have been employed to characterize the physical properties of surfactants in solution and the sizes and shapes of the micelles they form.…”

“…surface tension, viscometry, X-ray scattering (3,9,10), pulsed field gradient NMR (3,11), fluorescence quenching (3,4), and quasi-elastic light scattering (3,(6)(7)(8). It was found that the critical micelle concentration (cmc) of nonionic surfactants tends to be significantly lower than that of ionic surfactants, and for surfactants of similar EO x length the cmc values decrease strongly with increasing alkyl chain length (4).…”

Diffusion Coefficients of Three Organic Solutes in Aqueous Sodium Dodecyl Sulfate Solutions

“…Equation [15] is similar to an equation due to Armstrong et al (21), which was derived from Eq. [1].…”