Mesoscopic structure in near-critical mixtures of D2O and 3-methylpyridine with salts

Abstract

Small-angle neutron scattering (SANS) experiments were performed on mixtures of 3-methylpyridine, D2O, and salts to investigate concentration fluctuations and structures in the vicinity of the critical point. The SANS profiles of ternary mixtures with large critical temperature shifts can be analyzed by the sum of the concentration fluctuation and a scattering from spherical clusters. The size of the clusters increases as the critical point is approached. These results can be interpreted in terms of a strong coupling of the critical fluctuation and the solvation effect of salt ions. © International Union of Crystallography 2007.