Theory 26/Solvation & interfaces/Hydration layers
Hydration Layer Is Charge Against Salt
The claim
The thickness of a protein's hydration layer is set by the ratio of surface charge to ionic strength, so added salt collapses it.
01Mechanism
Charged groups hold water while ions screen them; the ratio sets how far ordering extends.
02Prediction
Thickness should track the ratio.
03Refutation
Thickness tracking surface area would remove charge.