Parts | Days | Selection | Search | Updates | Downloads | Help
DY: Fachverband Dynamik und Statistische Physik
DY 32: Soft Matter II
DY 32.5: Talk
Friday, March 30, 2012, 11:00–11:15, MA 144
Bifurcations of films of binary liquid mixtures on a solid substrate and with a free surface — Fathi Bribesh1, •Santiago Madruga2, and Uwe Thiele1 — 1Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire, LE11 3TU, UK — 2ETSI Aeronauticos, Universidad Politécnica de Madrid, 28040 Madrid, Spain
Model-H is used to describe the phase separation of a free surface film of a binary liquid mixture on a horizontal solid homogeneous substrate [see e.g., U. Thiele, S. Madruga and L. Frastia, Phys. Fluids 19, 122106 (2007)]. We consider the incompressible and isothermal case. The spatial distribution of the two components of the mixture is characterised by the local difference in concentrations. The upper surface of the film (liquid-gas interface) is free to move and characterised by the film thickness profile. The present study focuses on (i) the linear stability (in time) of steady stratified (layered) critical films and (2) fully two-dimensional steady states characterised by their concentration profiles and film thickness profiles for the critical (mean concentration equals zero) and off-critical (mean concentration does not equal zero) cases. The bifurcation structure is determined for various steady states employing as control parameter the lateral domain size and mean concentration for the critical and off-critical case respectively. Thereby the mean film thickness and the energetic bias at the free surface (corresponding to a linear Marangoni effect) are fixed at several particular values.
We acknowledge support by the EU (PITN-GA-2008-214919).