A thermodynamic investigation on the micellization behavior of ionic liquid in presence of vitamins

Abstract

Abstract Herein, we have scrutinized the influence of vitamin B3 (nicotinic acid) and its isomer isonicotinic acid at varying concentrations on the micellization properties of 1-tetradecyl-3-methylimidazolium bromide [C14mim] [Br] at a given temperature range of 298.15–308.15 K to further explore their advancement in medicinal chemistry. The behavior of ionic liquid at the surface was determined using tensiometry, while conductivity, steady-state fluorescence, and UV–visible spectroscopy were used to determine the behavior in bulk. Various thermodynamic, surface, and micellization parameters have been determined. The evaluated CMC values for the pure ionic liquid were found to increase with the increasing concentration of external additives (nicotinic acid and isonicotinic acid). Further, the negative ∆ G m i c 0 ${{\increment}G}_{\mathrm{m}\mathrm{i}\mathrm{c}}^{0}$ and ∆ H m i c 0 ${{\increment}H}_{\mathrm{m}\mathrm{i}\mathrm{c}}^{0}$ state the feasible and exothermic nature of the micellization process. The results attained employing different methods were correlated with each other and are found to be in good agreement. The results obtained from various studies indicate the presence of hydrophobic and electrostatic interactions occurring between the additives (nicotinic and isonicotinic acid) and the ionic liquid aggregates.