Aggregation Behavior Of Cationic Surfactant Research Articles

Influence of Morpholinium-Based Ionic Liquid on the Aggregation Behavior of Cationic Surfactant and Imidazolium-Based Ionic Liquid with the same Alkyl Chain in an Aqueous Medium

Influence of Morpholinium-Based Ionic Liquid on the Aggregation Behavior of Cationic Surfactant and Imidazolium-Based Ionic Liquid with the same Alkyl Chain in an Aqueous Medium

Modulation in Aggregation Behavior of Cationic Surfactant in Presence of Fluoroquinolone Drug: A Physicochemical Approach

AbstractMeasurements of density, speed of sound, conductivity, and fluorescence spectroscopy have been carried out to study the interactions between cationic surfactant cetyltrimethylammonium bromide in an aqueous solution of the fluoroquinolone drug at different concentrations and temperatures. Volumetric and compressibility parameters, such as apparent molar volumes ( V φ), isentropic compressibility ( κ s), and apparent molar isentropic compressibility (κ φ, s), have been obtained from density and speed of sound. The critical micelle concentration (CMC) of cetyltrimethylammonium bromide (CTAB) is found to decrease with an increase in [antibiotic drug] and increase with an increase in temperature, accounting for the fact that hydrophilic dehydration plays a decisive role for micellization to take place. The various thermodynamic parameters indicate the spontaneity of micellization in the presence of drug moiety. The CMC values have been calculated using pyrene as a fluorescent probe at room temperature, and a good qualitative correlation is found to exist well with the CMC values determined using speed of sound and conductivity measurements.

Studies on cetyltrimethylammonium bromide (CTAB) micellar solution and CTAB reversed microemulsion by ESR and 2H NMR

ESR spectroscopy was used in this study to monitor the aggregation behavior of cationic surfactant [cetyltrimethylammonium bromide (CTAB) in aqueous solution by measuring the rotational correlation time τ of a nitroxide labeled fatty acid probe (5-doxyl stearic acid) as a function of the surfactant concentration. The critical micelle concentration (CMC) of CTAB micelle in aqueous solution was obtained. The CMC value of CTAB micelle solution obtained by ESR spectroscopy is in good accordance with that obtained by the surface tension method. ESR studies on CTAB/n-butanol/octane/H 2O reversed microemulsion showed that the probe motion becomes more anistropic with increase in water content W 0 = [ H 2 O] t [ CTAB] t . From 2H NMR spectra it is concluded that the free water content becomes larger with increase in W 0, and five water molecules are tightly bound to one CTAB molecule.