Fluorimetric determination of structural parameters of BuOH/SDS/H2O reverse micelles

A steady-state fluorescence quenching study was undertaken to estimate aggregation numbers, N, and radii for the cell, r(e), and for the water pool, r(e), of sodium dodecyl sulfate, SDS, BuOH and water reverse micelles at a fixed [H2O]/[SDS] = 42.7 ratio, which allows variations in the percentage of BuOH in the system ranging 50-90%. For the purpose, pyrene was employed as fluorescent probe and N-cetylpiridmium chloride as static quencher. The results obtained show that N values, which range 8-33, show a linear variation with the amount of surfactant present in the system: meanwhile r(wp) values are mainly determined by the water content. The minimal water content and the minimal r(wp) value for reverse micelle formation were also estimated. (C) 2004 Elsevier B.V. All rights reserved.