Review on conductometric, volumetric and computational studies on surfactants-amino acids interactions

In this review amino acid-surfactant interactions mainly in aqueous solution has been explained. Amino acids and surfactants interactions are important in many studies because of their enhanced effectiveness in both living and non-living worlds. As physicochemical properties are additive, the study of interactions between amino acids and surfactants offer insights into how proteins unfold and denaturate in various media, which further alters with a change in physiological parameters like pH, additives, no of carbon in the chain and temperature. Keeping this in mind, in this review main emphasis has been on conductometric, volumetric and computational studies for detailed exploration of solute–solvent interactions of amino acids and surfactants in aqueous medium and effect of temperature on these interactions. Conductance data has been used to find the critical micelle concentration (CMC) of the surfactant. Using CMC, standard Gibbs free energy of micellization, ( \({\Delta G}_{{\text{m}}}^{{0}}\) ${\mathrm{\Delta }G}_{\text{m}}^0$ ), enthalpy of micellization, ( \({\Delta H}_{{\text{m}}}^{{0}}\) ${\mathrm{\Delta }H}_{\text{m}}^0$ ), entropy of micellization, ( \({\Delta S}_{{\text{m}}}^{{0}}\) ${\mathrm{\Delta }S}_{\text{m}}^0$ ) have been determined for surfactant in presence of amino acids. In volumetric investigation, density data has been utilized to find apparent molar volumes of amino acids, (ϕ_v) and partial molar volume (ϕ⁰_v), which is used to find soute-solvent interaction. In computational studies the effects of carbon tail length on CMC and aggregation number, (A_g) for the pure Gemini surfactant system were examined and these data were compared with experimental results to find the agreement between different methods.