Study of the reaction of ninhydrin with tyrosine in gemini micellar media

This paper reports the study of the ninhydrin and l-tyrosine (Tyr) reaction in gemini micellar media. The aim of the study was to see the influence of different parameters on the reaction rate, including the influence of reactant concentration, temperature and pH. Spectrophotometric and conductometric techniques were employed to record the absorption of the product formed and cmc values as a function of the surfactants, respectively. The effect of varied surfactant concentrations on the reaction rate was also investigated. The quantitative treatment of the rate constant (k ψ) vs. surfactant concentration was carried out on the basis of the pseudo-phase model suggested by Martinek et al., Menger and Portnoy, and established by Bunton. Micellar binding parameters and thermodynamic parameters have been calculated and are discussed in detail. A plausible reaction mechanism that is consistent with observed kinetic data has been proposed.

Surfactant-Amino Acid and Surfactant-Surfactant Interactions in Aqueous Medium: a Review

An overview of surfactant-amino acid interactions mainly in aqueous medium has been discussed. Main emphasis has been on the solution thermodynamics and solute-solvent interactions. Almost all available data on the topic has been presented in a lucid and simple way. Conventional surfactants have been discussed as amphiphiles forming micelles and amino acids as additives and their effect on the various physicochemical properties of these conventional surfactants. Surfactant-surfactant interactions in aqueous medium, various mixed surfactant models, are also highlighted to assess their interactions in aqueous medium. Finally, their applied part has been taken into consideration to interpret their possible uses.