Study of Micellar Behavior of Crown Ether and Tetraethylammonium Bromide in Aqueous Media

R D Singh,Rajni Garg

doi:10.1155/2010/927642

Abstract

Conductivity measurements have been carried out to study the micellar behavior of tetraethylammonium bromide in presence of 15-crown-5 in aqueous media. The measurements were carried out at 298.15 K as a function of surfactant concentration with varying concentrations of crown ether. The influence of this association on the micellar parameters, such as the cmc (critical micellization concentration) and β (degree of counterion dissociation) have been analyzed. Thermodynamics of the systems were discussed in terms of the change in free energy of micellisation, ΔG0mby applying the charged pseudo-phase separation model. The trend shows that the micellization becomes less spontaneous in presence of crown ether. The influence of the presence of the inclusion complex on the micellization process of the surfactant has been studied.

Highlights

Surfactant organized assemblies have great potential applications in day to day life
Conductivity technique has been widely used to obtain the cmc of pure or mixed ionic surfactants in water[2,3,4,5,6,7,8,9,10,11,12,13,14] and is important tool to study the thermodynamics of the systems
The ratio between the slopes of the post-micellar region to that in the pre-micellar region gives the degree of counterion dissociation, β Figure 3 shows the variation of β for the ternary tetraethylammonium bromide (TEAB) /CE/W systems as a function of concentration of crown ether

Summary

Introduction

Surfactant organized assemblies have great potential applications in day to day life. Surfactant solutions at times are characterized by micelle formation at a particular concentration known as cmc. Efforts have been made to study the effect of addition of crown ether, 15-crown-5 (CE) on the cmc of aqueous solutions of anionic tetraethylammonium bromide (TEAB) using conductivity technique.

Results

Conclusion