Surface adsorption and thermodynamic properties of mixed system of ionic liquid surfactants with cetyltrimethyl ammonium bromide

Abstract

The effects of temperature and concentration of CTAB added to imidazolium-based ionic liquids (CnmimBr, n = 10, 12, 16) were investigated, and surface active parameters and aggregation of these surfactants were explored by surface tension and conductivity measurements.

Effects of temperature and polyols on the ciprofloxacin hydrochloride-mediated micellization of sodium dodecyl sulfate

“…The DG m values for all systems (SDS/SDS + CFH in aqueous as well as in polyols (glucose or fructose) media) were negative, which shows that the micellization phenomena are thermodynamically spontaneous. 2,11,67 The observed DG m value of SDS alone was found to be higher than those of the SDS + CFH mixed system both in aqueous and polyols (glucose or fructose) media, which signies that pure SDS undergoes micellization more spontaneously than the SDS + CFH mixture. The negative DG m for the micellization of individual SDS in aqueous medium is enhanced as the temperature elevates, indicating that the association phenomena are additionally spontaneous at the higher studied temperatures; therefore, cmc is lower at higher temperature (Table 1).…”

Micellization, surface activities and thermodynamics study of pyridinium-based ionic liquid surfactants in aqueous solution

“…In this equation, pC 20 is the negative log of the ILs surfactants concentration which reduce the surface tension of the pure solvent by 20 mN m À1 . 22,23,38 Effectiveness of surface tension reduction (P cmc ). To show the ability to decrease surface tension of solutions, the effectiveness of the surface tension reduction (P cmc ) is dened as:…”

“…where g 0 is the surface tension of bidistilled water and g cmc is the surface tension of the solutions at CMC. 22,23,38 Maximum surface excess concentration (G max ). The maximum surface excess concentration (G max ) at the air/water interface was estimated by applying Gibbs adsorption isotherm:…”

“…As there is one counter ion associated with one ionic head group, the value of n is taken to be 2. 18,20,38 Minimum surface area (A min ). Minimum surface area (A min ) provides information on the degree of packing and orientation of the adsorbed surfactant molecule.…”

“…The enthalpy of micellization (DH q m ) can be determined by using the Gibbs-Helmholtz equation: 21,38 DH q m ¼ À2:3 Â ð2 À bÞRT 2 vðlog c CMC Þ vT…”