LAUSR

Abstract Observation of the relations of the beta-lactum antibiotic drug levofloxacin hemihydrate (LFH) with of tetradecyltrimethylammonium bromide (TTAB) has been carried out by conductivity measurement technique in aqueous solution of alcohols and polyols at single fixed temperature (303.15 K) for different concentrations and at different temperatures (298.15–318.15 K) with interval of 5.0 K for one selected fixed concentration. For TTAB + LFH mixture with alcohols/polyols, a single critical micelle concentration (cmc) was found in this study. In presence of alcohols, the values of cmc for mixed systems LFH + TTAB exhibited higher (except for ethanol at 298.15 K) in magnitude in compare to their absence. This showed that the micellization of the mixture of LFH and TTAB was unfavorable to some extent in attendance of alcohols. In attendance of polyols, the cmc values for mixed systems LFH + TTAB was obtained smaller in scale in compare to their absence. This exhibited the early micellization of the mixture of LFH and TTAB. Values obtained for ΔG0m were negative, which indicate naturalness of the present study. The other kinds of thermodynamic parameters such as transfer enthalpy (ΔH0m.tr), transfer free energy (ΔG0m.tr), and transfer entropy (ΔS0m.tr) were also observed and demonstrated carefully. The compensation temperature (Tc) as well as the intrinsic enthalpy gain (ΔH0⁎m) were also determined and interpreted. Moreover, the standard molar heat capacity (ΔC0m) for mixed system was evaluated and explained for the studied system.