Theory 24/Solvation & interfaces/Contact angle hysteresis
Hysteresis Is Pinning Against Volume
The claim
Contact angle hysteresis is set by the ratio of pinning energy to droplet volume, so small droplets are more strongly pinned.
01Mechanism
Defects hold the contact line; the energy to move it scales with the defect while the driving force scales with volume.
02Prediction
Hysteresis should rise as droplets shrink.
03Refutation
Hysteresis independent of volume would remove pinning.