EFFECT OF 1-ALKANOLS ON THE CRITICAL MICELLE CONCENTRATION OF SODIUM DODECYL BENZENE SULFONATE

The critical micelle concentration (CMC) of sodium dodecyl benzene sul fonate (SDBS) in the presence of small amounts of l-alkanols (C-1-C-4, C-6, C-8) was determined by the conductivity method at 25 degrees C. T he CMC decreases linearly with an increase in the concentration (C-a) of the added l-alkanols, within their low concentration ranges. The li miting slopes (-Delta CMC/Delta C-a) were estimated from the straight lines for each alcohol. Using these slopes the standard free energy ch ange of transfer per methylene (CH,) group, Delta G degrees(CH2), from water to SDBS micelles has been calculated. Solubilization of l-alkan ols by SDBS has been discussed in terms of additive-micelle hydrophobi c interaction.