The mixed micelles C12E4 (tetraethylene glycol mono-n-dodecyl ether)/CTAB (hexadecyltrimethylammonium bromide) were studied. The surface tension results were analyzed on the basis of a treatment that considers the relation between the activity coefficients according to the Gibbs−Duhem equation. The results are compared with Rubingh's treatment, which considers the activity coefficients given by the regular solution theory. The conductivity of the samples and the aggregation numbers at low mixture concentration are also given.

Steady-state fluorescence and molecular mechanics calculations were used to study the inclusion complexes of 9-methyl anthracenoate (MA) and 1-methyl pyrenoate (ΜP) with -cyclodextrin ( CD). Binding constants of 1:1 complexes at different temperatures were obtained from the analysis of the fluorescence enhancement of the CD solutions with respect to the MA or MP free chromophores. The thermodynamic parameters ∆H and ∆S were also obtained. Molecular mechanics calculations were applied to study both inclusion processes in vacuo and in the presence of water as a solvent. Complexation is mainly due to nonbonded van der Waals host-CD interactions. Both MA and MP penetrate only partially into the CD cavity.