B05

B05: Molekulare Modellierung komplexer Fluide im Bereich der Dreiphasenkontaktlinie

Static and dynamic properties of three-phase contact lines (TPCLs) are poorly understood. The picture shows a liquid bridge between two solid surfaces with a vertical dimension of ~ 50 nm. The static electro-wetting contact angles are indicated as well. Molecular Dynamics (MD) simulations (F. Taherian et al. Langmuir (2015) 31, 4686) indicate that the static contact angle responds asymmetrically upon switching the sign of the surface charge density, while the bulk interfacial (solid-liquid) free energy remains unchanged. The observed effect is caused by differences in the molecular structure and free energies of the two TPCLs on oppositely polarised surfaces. The implications of these differences for contact line friction and dynamics will be investigated in TP B05 (amongst other effects and systems). The MD simulations performed in TP B05 provide atomic-level understanding of TPCL properties and provide information on hydrodynamic boundary conditions in continuum fluid mechanics models for fluid mixtures. Image: Nico van der Vegt
Static and dynamic properties of three-phase contact lines (TPCLs) are poorly understood. The picture shows a liquid bridge between two solid surfaces with a vertical dimension of ~ 50 nm. The static electro-wetting contact angles are indicated as well. Molecular Dynamics (MD) simulations (F. Taherian et al. Langmuir (2015) 31, 4686) indicate that the static contact angle responds asymmetrically upon switching the sign of the surface charge density, while the bulk interfacial (solid-liquid) free energy remains unchanged. The observed effect is caused by differences in the molecular structure and free energies of the two TPCLs on oppositely polarised surfaces. The implications of these differences for contact line friction and dynamics will be investigated in TP B05 (amongst other effects and systems). The MD simulations performed in TP B05 provide atomic-level understanding of TPCL properties and provide information on hydrodynamic boundary conditions in continuum fluid mechanics models for fluid mixtures. Image: Nico van der Vegt

Teilprojekt B05 zielt auf das Verständnis der Wechselwirkung von Transport- und Benetzungsvorgängen auf molekularer Ebene ab. Zudem liefert es makroskopische Modellparameter durch molekulare Betrachtung der Materie in ihrem physiko-chemischen Verhalten. Schwerpunkte sind die Zusammenhänge zwischen Fluid-Festkörper-Interaktionen an glatten homogenen oder chemisch heterogenen Oberflächen. Aus MD-Simulationen werden zudem Parameter der Randbedingungen (wie z.B. Schlupflänge) z.B. in Surfactant-Systemen ermittelt und in kontinuumsmechanische Simulationen in OpenFOAM eingespeist. Gemeinsam mit anderen Teilprojekten aus B (insb. B01, B02) soll letztlich eine hierarchische Mehrskalenmodellierung erarbeitet werden.