Role of Interfacial Rigidity of Aerosol OT Reverse Micelle (RM) on the Kinetics of Chromium-EDTA Complexation Reaction

The inter droplet interaction forces among the reverse micellar (RM) droplets are dependent on the interfacial rigidity of the surfactant monolayer film. Here we report in details the interfacial rigidity dependent reaction kinetics study of chromium-EDTA complexation in RM system comparing the results obtained in aqueous solution. The interfacial rigidity of the surfactant monolayer has been controlled by adding cholesterol in the RM system. The chromium-EDTA complexation reactions are discussed in terms of thermodynamic parameters. Cholesterol enhance the interfacial rigidity of the surfactant film and hence it enhances the activation energy but decreases the enthalpy and the entropy of the process compared with the reaction in aqueous medium.