Theory 19/Colloid Science
Stability Is a Length Ratio
The claim
Colloidal stability is set by the ratio of electrostatic screening length to van der Waals attraction range rather than by surface charge alone.
01The mechanism
Stability requires the electrostatic barrier to exceed the attraction at the separation where attraction is strongest; the ratio of the two length scales sets that balance.
02Predictions
- P1Stability should track the ratio.
- P2Charge alone should mispredict across salt concentrations.
03Refutation
Stability tracking surface charge would remove the length ratio.