Hofmeister series

[5] The order of the tendency of ions to make or break water structure is the basis of the Hofmeister series.

[10] Simulation studies have shown that the variation in solvation energy between the ions and the surrounding water molecules underlies the mechanism of the Hofmeister series.

[13] This work provides site-centred radial charge densities of the ions' interacting atoms (to approximate the electrostatic potential energy of interaction), and these appear to quantitatively correlate with many reported Hofmeister series for electrolyte properties, reaction rates and macromolecular stability (such as polymer solubility, and virus and enzyme activities).

Early members of the series increase solvent surface tension and decrease the solubility of nonpolar molecules ("salting out"); in effect, they strengthen the hydrophobic interaction.

At high salt concentrations lysozyme protein aggregation obeys the Hofmeister series originally observed by Hofmeister in the 1870s, but at low salt concentrations electrostatic interactions rather than ion dispersion forces affect protein stability resulting in the series being reversed.