Berlin 2008 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 42: Layer Growth: Evolution of Structure and Simulation
DS 42.1: Vortrag
Freitag, 29. Februar 2008, 16:15–16:30, H 2032
Numerical simulation of demixing of a binary mixture on the solid substrate with a free surface — •Lubor Frastia^{1} and Len M. Pismen^{2} — ^{1}MPG PKS, Nöthnitzer Straße 38, 01187 Dresden, Germany — ^{2}Dept. of Chemical Engineering, Technion, 32000 Haifa, Israel
The problem of simultaneous demixing and dewetting is frequently occuring in nano-technological applications, where the thickness of the internal interfaces in the phase-separated liquid may be comparable to the droplet size or layer thickness. Theoretical approaches to the demixing problem are commonly based on the Cahn–Hilliard theory [1] using the Landau–Cahn free energy functional approximation to model phase separation while neglecting the effects of the moving surfaces [2].
In this contribution, we describe the static limit of the model, given in [3], specialized for a 2D film lying on a solid substrate. Based on this model, we derived the Finite Element (FE) numerical procedure and computed droplet solutions for selected parameters of the model, using a continuation procedure with surface tension of the free surface, γ, as the continuation parameter. Resulting solution branch is compared with the related circular-symmetric droplet solution and its effective sharp interface approximation.
References:
- 1. J.W. Cahn and J.E. Hilliard, J. Chem. Phys. 28, 258–267 (1958).
- 2. H.P. Fischer, P. Maass, and W. Dieterich, Europhys. Lett. 42, 49–54 (1998).
- 3. U. Thiele, S. Madruga, L. Frastia, submitted to Physics of Fluids.