Interaction of DL-Valine/DL-Serine with Cationic and Anionic Surfactants in Aqueous Media: Volumetric, UV-visible Spectroscopic, and Conductometric Studies

Abstract: In the present work, the volumetric and conductometric studies to find the interactions between amino acids DL-Valine and DL-Serine with cationic and anionic surfactants, cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) in aqueous solutions at different temperatures and atmospheric pressure were carried out. The effect of pre- and post-micellar concentrations of surfactants on the physicochemical properties was also studied. The densities measured experimentally were used to calculate the thermodynamic parameters such as the apparent molar volumes, ϕ_v, partial molar volumes,, transfer volumes, (tr), and partial molar expansibilities, at temperatures from 288.15 to 303.15 K while the conductivity data obtained at different temperatures from 293.15 to 318.15 K were used to obtain the molar conductivities () as well as limiting molar conductivities () from specific conductivities (κ) which reflect the interaction prevailing within the studied systems. In addition, the UV-visible absorption spectroscopy at 298.15 K has also been performed in the presence of fluorescein to study the interaction within above mentioned systems.