According to Wikipedia, contact angle depends on the hydrophobicity of the surface and on thermodynamic equilibrium. But how does it in theory depend on the drop size? In other words, how would a theoretical curve of contact-angle ($\theta$) vs. drop-volume ($V$) look like, for a given surface?
- According to Drelich et. al. and to Good & Koo, in some liquids there's dependence, while in other the dependence is very weak.
- According to attension TN6, droplet volume "has significant influence on contact angle only with substrates that have large contact angle hysteresis (e.g. due to chemical heterogeneity and surface roughness)".
- According to C. Elif Cansoy, on superhydrophobic surfaces there's very small dependance between contact angle and drop volume.