Concentration fluctuation and salt-induced percolation in 1-propanol aqueous solution

Temperature dependent Kirkwood-Buff parameters G(pp), G(ww) and G(pw) have been evaluated for the l-propanol-water solution (1:5 in mole ratio) from S-cc(0) obtained by small angle neutron scattering (SANS) experiments. Structural model for the concentration fluctuation for the solution at 25 degreesC has been constructed based on the value of G(pp). Characteristic feature of the SANS intensity and fractal nature of the concentration fluctuation can be explained qualitatively by the model structure. The volume fraction w, of propanol-rich regions in the solution has been estimated as a function of temperature. Salt-induced phase separation phenomena observed on the current solution is discussed based on the temperature-dependent percolation theory.