Conductometric Study of Short Chain Alkanones and Alkyl Acetates within Anionic Micelles

The interaction of short chain alkanones and alkyl acetates (alkyl group = methyl to propyl) with the micelles of an anionic surfactant, sodium dodecyl sulfate (SDS), was studied by the conductivity method at 25.0°C. The critical micelle concentration (CMC) of SDS decreases linearly with the increase in the concentration of additives in the low concentration regions. The water-micelle partition coefficient, K_x, and the standard free energy change of penetration, ΔG⁰_P, of each additive from water to micelle were calculated from the limiting slope (dCMC/dC_a). The free energy change per methylene group, AΔG⁰(CH₂), has also been evaluated. The K_x values for a given additive increases with the increase in alkyl chain.