Properties of Concentrated Aqueous Electrolyte Solution in a Vicinal Region of Coexisting Solid Surface

Abstract

Properties of concentrated ZnSO4 aqueous solutions coexisting with metal oxide nanoparticles were observed. Raman spectroscopy indicated that ion pair forming tendencies was enhanced in the vicinity of silica nanoparticles which have hydrophilic groups. Zn2+ is supposed not to make sufficient hydration sphere and tend to make contact ion pair due to sharing water molecules with hydrophilic solid surface. Alumina nanoparticles exhibited strong effect on 1H relaxation than silica nanoparticles. The salt concentration dependences of 1H relaxation time and pH of aqueous solution suggested that the effects from solid phase on coexisting liquid phase were affected by liquid property in itself.