Electrostatics in Macromolecular Solutions - Food Colloids: Self-Assembly and Material Science - page 132

Figure 2 Individual activity factors fromMC simulations and from DH theory for a hard-

core diameter of 4 A ˚ . The logarithm of the activity factor g is plotted against salt
concentration c s : (a) monovalent ion in 1:1 and 2:1 electrolytes; and (b)
divalent ion in a 2:1 electrolyte. The arrows indicate the physiological salt
condition

in pH (meaning that the net charge on both ligand and macromolecule can
vary). These changes will affect the electrostatic interactions and they are
almost quantitatively captured by the activity factors. The simplest approach
would then be to treat the macromolecule as a charged spherical object and
directly apply Equation (4).