文摘
In the present study, the interaction of an anionic azo dye, Sunset Yellow, with two cationic gemini surfactants with different spacer lengths (s?=?3, 6 methylene groups) and their monomeric counterpart, dodecyl trimethyl ammonium bromide (DTAB), was investigated by surface tension, UV-Vis spectroscopy, and zeta potential measurements. The critical micelle concentration (CMC) was determined from plots of the surface tension (¦Ã) as a function of the logarithm of total surfactant concentration. Moreover, the values of binding constants (Kb) of dye-surfactant complexes were calculated by UV-Vis spectroscopy. The UV-Vis spectra showed that the dye-surfactant interaction occurred in the solution at concentrations far below the CMC of each surfactant. The gemini surfactant with a shorter spacer showed stronger interaction with dye in comparison to DTAB and the gemini with longer spacer. The effect of surfactant chemical structure on solubilization of dye-surfactant aggregates at surfactant concentration above CMC was investigated by zeta potential.
