• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.556-562
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• 2012

The critical micelle concentration (CMC) and the counter-ion binding constant (B) for the mixed micellizations of TTAB (tetradecyltrimethylammonium bromide) with other surfactants (DTAB, CTAB, Tween-20, Tween-40, and Tween-80) in aqueous solution of 4-chlorobenzoic acid (0.5 mM) at $25^{\circ}C$ were determined as a function of ${\alpha}_1$ (the overall mole fraction of TTAB) by using the spectrophotometric method and the conductivity method. Various thermodynamic parameters ($X_i$, ${\gamma}_i$, $C_i$, $a_i^M$, ${\beta}$, and ${\Delta}H_{mix}$) were calculated for each mixed surfactant system and compared with the other mixed surfactant systems by means of the equations derived from the nonideal mixed micellar model. The results show that TTAB/DTAB mixed system has a great positive deviation from the ideal mixed micellar model and the other mixed systems have great negative deviations from the ideal mixed model.

• Journal of the Korean Applied Science and Technology
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• v.37 no.3
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• pp.438-447
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• 2020

The critical micelle concentration (CMC) values of the mixed surfactant systems and the solubilization conatant (K_s) values of 4-ethylaniline in those solutions were measured and analyzed by the UV-Vis method. As a result, the mixed surfactant systems of TTAB/LSB and TTAB/TX-100 did not deviate significantly from ideal mixed micellization. However, the mixed systems of SDS/LSB and SDS/TX-100 showed great negative deviations from ideal mixed model. These differences showed that the intensity of the interaction between two components in the mixed micelle was different for each mixed system and that these differences greatly influenced the solubilization of 4-ethylaniline by a mixed surfactant system. Among pure surfactants, an anionic surfactant such as SDS showed a greater K_s value than other ionic surfactants, and the K_s value by each surfactant system decreased in the order of SDS≫TTAB≧LSB>TX-100. In addition, the K_s values of all the mixed surfactant systems were higher than those of the pure surfactants constituting the mixed systems.