Theory 30/Solvation & interfaces/Hydrogels
Swelling Is Osmosis Against Elasticity
The claim
Hydrogel swelling is set by the ratio of osmotic pressure to elastic modulus, so a stiff gel holds less water at the same ionic environment.
01Mechanism
Water enters until network tension balances osmotic draw.
02Prediction
Swelling should track the ratio.
03Refutation
Swelling tracking crosslink density would remove osmosis.