competitive binding at the surface of dodecylsulfate/brij 35 mixed micelles

The Binding of Short-Chain N-Alkylpyridinium Ions to Sodium Dodecyl Sulfate Micelles

“…The selectivity constants obtained, 13 ± 1 and 47 ± 1 for NEP + /Na + and NPP + /Na + , respectively, suggest that the higher value for NPP + cation is ascribed to an electrostatic field contribution in addition to a specific adsorption potential due to the size of the hydrophobic chain (17), reducing the alkyl chain-water contacts of both the organic cation and surfactant monomer. These results show that the selectivity is determined by the nature of the counterions present and it is less dependent on the characteristics of the micellar aggregates (10,11). …”

“…A combination of Eqs. [9] and [11] indicates that log k − is a linear function of log [Y aq ] with a slope equal to (z x /z y )β (16-18)…”

“…The micellar surface potential is logarithmically related to the concentration of free micellar counterions ([Y aq ]) in the aqueous phase (27,28), [11] where K y is a constant. A combination of Eqs.…”

Counterion Exchange Selectivity in Detergent–Polymer Aggregates

“…Indeed, for a given ionic detergent headgroup type, monovalent counterion exchange selectivity is usually found was present and the number of bound quencher counterions was restricted to less than one per micelle or aggregate. to be rather insensitive to aggregate size, surface curvature (32,33) or moderate changes in aggregate surface charge Under these conditions, the statistical distribution of the bound quencher can be safely approximated by a Poisson density (15). The divalent counterion MV 2/ exhibits a somewhat lower selectivity and Cu 2/ a distinctly higher sedistribution and any effects of the small amount of added quencher counterion on a, the cmc or cac, and the aggrega-lectivity at the surface of the SDS-PEG aggregates.…”

“…ion exchange have been determined from steady-state (11)(12)(13)(14)(15) and time-resolved (16) measurements of the quenching of the fluorescence of micelle-solubilized aromatic hydrocarOne of the most extensively studied detergent -polymer bons by counterions. In the present work, we have employed interactions is that between the anionic detergent sodium two photophysical probe techniques to determine counterion dodecyl sulfate ( SDS ) and the nonionic polymer poly ( -exchange selectivities at the surface of SDS-PEG clusters.…”