Fingering phenomena during spreading of surfactant solutions

Fingering instabilities are observed at the contact line of drops of surfactant solutions spreading spontaneously Oil solid surfaces coated by a film of solvent. The occurrences of instabilities, and the characteristics of the instability pattern, are controlled by the surfactant concentration and the thickness of the film adsorbed or deposited on the substrate. This work provides experimental data as a basis for forthcoming theoretical analyses. (C) 2004 Elsevier B.V. All rights reserved.