Related Experiment Video
Updated: Jul 19, 2026

Generation of Size-controlled Poly (ethylene Glycol) Diacrylate Droplets via Semi-3-Dimensional Flow Focusing Microfluidic Devices
Published on: July 3, 2018
Contact line dynamics in the late-stage coalescence of diethylene glycol drops
1Equipe du Supercritique pour l'Environnement, les Matériaux et l'Espace, Ecole Supérieure de Physique et Chimie Industrielle, Laboratoire de Physique et Mécanique des Milieux Hétérogènes, rue Vauquelin, 75231 Paris Cedex 05, France. daniel.beysens@cea.fr
Abstract:
We investigated the contact line dynamics of a composite drop formed as a result of the coalescence during the condensation of two diethylene glycol (DEG) drops at -4 degrees C on a silicon surface. The composite drop relaxes exponentially toward equilibrium with a typical relaxation time, tc, which depends on the equilibrium radius, R, of the composite drop. The value of tc is found to be in the range of 10-100 s for R approximately 1-4 microm. The relaxation dynamics is found to be larger by 6 orders of magnitude than that predicted by bulk hydrodynamics because of high dissipation in the contact line vicinity. Similar to low viscous liquids (water), this high dissipation can be attributed to an Arrhenius factor resulting from the phase change in the contact line vicinity and to the influence of surface defects that pin the contact line.
Related Concept Videos
Colloidal precipitates
Excess Pressure Inside a Drop and a Bubble
Contact Angle
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive force...
Surface Tension of Fluid
Surface tension varies with...
Freezing Point Depression and Boiling Point Elevation
The boiling point of a liquid is the temperature at which its vapor pressure is equal to ambient atmospheric pressure. Since the vapor pressure of a solution is lowered due to the presence of nonvolatile solutes, it stands to reason that the solution’s boiling point will subsequently be increased. Vapor pressure increases with temperature, and so a solution will require a higher temperature than will pure solvent to achieve any given vapor pressure, including one...
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model

