Meniscus deformation and dynamics of moving contact line between poly(ethylene terephthalate) surface and glycerol-water mixtures

The microscopic hydrodynamic (HD) and macroscopic theories for describing the meniscus deformation and dynamics of a moving contact line have been analyzed and compared by using the extrapolated dynamic contact angles between a poly(ethylene terephthalate) (PET) surface and glycerol-water mixtures. The analysis showed that the microscopic theory is confined by the microscopic length scale and small capillary number. The macroscopic theory is not subjected to any restrictions. Three (inner, intermediate and outer) regions of the dynamic meniscus have been combined by using the contact molecular kinetics and hydrodynamics. The combined molecular-HD theory has been validated using the experimental data for the extrapolated dynamic contact angles between a PET surface and glycerol-water mixtures. The analysis showed that the combined theory describes the phenomenon of wetting qualitatively. It was found that the contradiction within the theoretical framework of the molecular kinetics and hydrodynamics hinders the exact description of the wetting phenomenon. (c) 2009 Curtin University of Technology and John Wiley & Soils, Ltd