Cationic and anionic effects on the homogeneous nucleation of ice in aqueous alkali halide solutions

Abstract

Homogeneous ice nucleation temperatures ( T Hs) of aqueous alkali halide solutions were measured as a function of salt concentration. Cationic effect on T H increases with decreasing ionic radius: Cs +<Rb +<K +<Na +<Li + while anionic effect becomes larger with increasing ionic radius: Cl −<Br −<I −. There is almost a linear relation between T H and 1/ r + (or 1/ r −) for the same halide (or alkali) solutions up to high salt concentrations ( r + and r − are ionic radii of alkali and halide ions, respectively).