Interactions of short chain phenylalkanoic acids within ionic surfactant micelles in aqueous media

Abstract

% SDS KR nema Solubilization and interactions of phenylalkanoic acids induced by cationic surfactant, cetyltrimethylammonium bromide (CTAB) and an anionic surfactant, sodium dodecyl sulfate (SDS) was investigated spectrophotometrically at 25.0?C. The UV spectra of the additives (acids) were measured with and without surfactant above and below critical micelle concentration (cmc) of the surfactant. The presence of alkyl chain in phenylalkanoic acids is responsible for hydrophobic interaction resulting in shift of the spectra towards longer wavelength (red shift). The value of partition coefficient (Kx) between the bulk water and surfactant micelles and in turn standard free energy change of solubilization (?Gp?) were also estimated by measuring the differential absorbance (?A) of the additives in micellar solutions.