Micellar properties of a potentially polymerizable itaconic acid-derived surfactant: Potassium dodecyl itaconate

Micellar properties of potassium dodecyl itaconate (KDI), an itaconic acid-derived surfactant, have been studied. KDI was found to micellize in alkaline aqueous medium ([KOH] = 0.01 M) at 20°C with a critical micelle concentration of (3 ± 0.3) × 10^-4 M. The micelle aggregation number was estimated as 80 ± 5 from a fluorescence quenching method. Solubilization behavior of KDI micelles toward a highly hydrophobic solute (n-pentane), an amphiphatic solute (n-hexanol), and an aromatic hydrocarbon (pyrene) was examined. The results obtained show that KDI micelles are better solvents than sodium dodecyl sulfate micelles for n-pentane. The solubilization behavior and the locus of incorporated n-hexanol and pyrene in KDI closely resemble those in sodium dodecyl sulfate, indicating that interfacial and core properties of both micelles toward this type of compounds are quite similar. Selectivity coefficients for Tl⁺ K⁺ and Tl⁺ Na⁺ counterion exchanges at the surface of dodecy itaconate micelles were also measured. The results obtained indicate that the degree of selectivity for the Tl⁺ Na⁺ counterion exchange is lower than that exhibited at the surface of sodium dodecyl sulfate micelles.