Microcalorimetric and condutivity studies of the effects of solutes on thepercolation behavior of reverse micelle systems

This study employed high sensitivity microcalorimetry to investigate the pe rcolation behavior of W/O microemulsions of AOT with and without solutes of salts, amino acids, and proteins. The dilution heat and the enthalpy behav ior of the reverse micelle solutions in the percolation process were measur ed by isothermal titration microcalorimetry (ITC). The enthalpy behavior re ported in this investigation supports qualitatively the association model o f percolation. The second virial coefficient of the interactions between re verse micelle droplets can be derived from the information of the dilution heat of the reverse micellar system with the concentration of the reverse m icelles and incorporating a hard-sphere interaction potential assumption. T he derived second Virial coefficients of different reverse micelle solution s are discussed along with the conductivity percolation temperature, and th e difference between the interaction potentials are in good agreement with the shift of the percolation temperature of various micellar systems. Visco sity measurements were also taken from of the micellar solutions in the pro cess of percolation in this study. A discussion on the relationship between the solute effects and the percolation in terms of the charge and the surf ace activity of the solutes is also included.