Festoon instabilities of slightly volatile liquids during spreading

C. Redon , F. Brochard-Wyart , F. Rondelez

We have observed two stages in the spreading of large, flat, droplets of silicone oils (degree of polymerization N < 20) deposited on bare silicon wafers : i) at first, the drop contour is perfectly circular and the drop radius R increases with time as R∼t0.15, ii) below a critical thickness hc, a rim is formed at the contact line and the contour develops spectacular festoons. At the same time, the spreading speeds up and the radius increases as R∼t1/3. We have interpreted these results in terms of Marangoni driven instabilities induced by the surface tension gradient generated at the drop edge by liquid evaporation.

Domaines: Articles anciens

C. Redon, F. Brochard-Wyart, F. Rondelez. Festoon instabilities of slightly volatile liquids during spreading. Journal de Physique II, 1992, 2 (9), pp.1671-1676. ⟨10.1051/jp2:1992226⟩. ⟨jpa-00247758⟩