NON-AGGREGATED SURFACTANT SYSTEMS AT HIGH-CONCENTRATION

Dielectric constant of the medium has been utilised to study the micel le-reverse micelle transition of linear alkylbenzene sulphonate (LAS). This transition with changing polarity of the medium is likely to enc ounter a monomeric state at an optimum dielectric constant of the medi um. Proton NMR spectroscopy has been utilised to study the aggregation behaviour of various isomers of LAS at very low and very high concent rations as function of dielectric constant of the medium. It is conclu ded that LAS remains in monomeric state even at very high concentratio ns in solvent systems with a dielectric constant around 41.