LAUSR

Isothermal titration calorimetric (ITC) study can probe critical micelle concentration (CMC) as well as the associated thermodynamics of surfactant aggregation. Micellization behavior of two bile salts, sodium cholate (NaC) and sodium deoxycholate (NaDC) were evaluated through ITC studies; subsequently the enthalpy change ( Δ H demic 0 ), Gibbs free energy change ( Δ G demic 0 ) and entropy change ( Δ S demic 0 ) of demicellization processes were also evaluated in the presence of varied concentration of an ionic liquid (IL) 1‐butyl‐3‐methylimidazolium tetrafluoroborate ([bmim]BF4) and at different temperatures at ascertain concentration of IL (1.0 mM). In order to distinguish the effect of IL from the corresponding common salt, studies were also carried out in aqueous sodium tetrafluoroborate (NaBF4) medium. CMC values decrease with increasing IL/NaBF4 concentration and increase with increasing temperature. CMC reduction in case of NaDC‐NaBF4 system is more prominent, while considering temperature variation, the CMC rise in NaC‐[bmim]BF4 system is more significant. Δ H demic 0 values considerably depend on temperature. Temperature rise causes an increase in Δ G demic 0 values. However, it decreases with increasing IL/NaBF4 concentration for both NaC and NaDC. Effect of temperature is less prominent on the Δ G demic 0 variation whereby the demicellization processes are found to be entropy driven processes. Temperature variation exhibits greater effect on Δ H demic 0 than the additive concentration. Such comprehensive studies hold promise for diverse scientific and industrial applications besides the fundamental understanding on IL induced micellization.