Micellization of Cetyl Triphenyl Phosphonium Bromide Surfactant in Binary Aqueous Solvents

Abstract

The effect of the different binary aqueous organic solvents viz. 1,4-dioxane, acetonitrile, dimethylsulfoxide, ethylene glycol, and methanol, on the micelle formation and thermodynamics of a cationic surfactant cetyl triphenyl phosphonium bromide has been studied conductometrically at 298-318 K. From the conductivity data critical micelle concentration, degree of counter ion dissociation (a) and thermodynamic parameters of micellization have been determined. It is observed that micellization tendency of the surfactant decreases in the presence of binary aqueous solvents. The entropies of micellization are all positive, and they compensate the enthalpies of the process.

Interaction of ionic liquid type cationic surfactants with triton X-100 nonionic micelles

“…Negative value of interaction parameter ␤m leads to decrease in CMC and other surface parameters for aqueous mixtures comprising nonionic and ionic surfactant [49]. These associative interactions can be explained in terms of decreased repulsion among ionic head group of cationic C n TPPBr in presence of non-ionic TX-100 molecules, ultimately promoting the micelle formation and resulting in low CMC compared to the individual surfactants [59]. In a similar report, the interactions of C n TPPBr with nonionic Tween-20 were studied by Al-Wardian and Palepu [49] using fluorescence and noticed strong synergism for Tween 20-TPPBr mixed micellar system.…”

“…Interaction of triblock copolymers and alkyl triphenylphosphonium bromides (n = 14,16) in aqueous mixed solutions was demonstrated by cloud point, relative viscosity and fluorescence measurements [58]. Thermodynamic parameters for micellization of aqueous C 16 TPPBr solutions in presence of different organic solvents are reported using conductometry [59].…”

Micellization behaviour and thermodynamic parameters of 12-2-12 gemini surfactant in (water+organic solvent) mixtures

“…In general, the enthalpy of the micellization is to be an exothermic process and decrease due to a change in the hydration of ionic head groups with temperature [35,43]. The values of negative enthalpy indicate that the London dispersion forces have a major importance for the micellization process.…”

Micellization of Cetyldiethylethanolammonium Bromide in Mixed Aqueous Organic Solvents

“…The acetonitrile disrupts the micelle formation due to the solvation of the hydrophobic part of the surfactant by the hydrophobic end of the surfactant by water, thus the increase in the CMC value. [22] The dielectric constant of DMF is much smaller than that of water. [23] This decrease in the dielectric constant would result in a small increase in the ionic interactions at the micellar surface; nonetheless, these interactions decrease rather than increase upon increasing the amount of DMF because of the increase in the ionic strength due to the increase in the monomer concentration provoked by the increase in the CMC.…”