M. Vignesadler et al., CONTACT LINE INSTABILITIES DURING DROP SP LASHING, Comptes rendus de l'Academie des sciences. Serie 2, Mecanique, physique, chimie, sciences de l'univers, sciences de la terre, 317(3), 1993, pp. 303-306
The splash of a droplet on a rough steel plate (R(a) = 5,000 angstrom)
is studied by fluorescence. Various instabilities of the contact line
are observed depending on the liquid. With pure water, the relaxation
of the contact line presents a festoon-shaped hysteresis similar to t
he one obtained on a surface with random weak defects, while with an e
mulsion a fingering instability is developed. The latter is attributed
to the different wetting properties of the two phases of the emulsion
. During the splash, the oil phase adsorbs further and it creates loca
lized anchored strong defects. The time scale (1 ms) of the phenomena
is remarkably small.