Concentration Fluctuation and Salt-Induced Percolation
in 1-Propanol Aqueous Solution

Abstract

Temperature dependent Kirkwood-Buff parameters G_pp, G_ww and G_pw have been evaluated for the 1-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°C 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.