title: Foam drainage control using thermocapillary stress in a two-dimensional microchamber.
abstract: We investigate the drainage of a 2D microfoam in a vertical Hele-Shaw cell, and show that the Marangoni stress at the air-water interface generated by a constant temperature gradient applied in situ can be tuned to control the drainage. The temperature gradient is applied in such a way that thermocapillarity and gravity have an antagonistic effect. We characterize the drainage over time by measuring the liquid volume fraction in the cell and find that thermocapillarity can overcome the effect of gravity, effectively draining the foam towards the top of the cell, or exactly compensate it, maintaining the liquid fraction at its initial value over at least 60 s. We quantify these results by solving the mass balance in the cell, and provide insight into the interplay between gravity, thermocapillarity, and capillary pressure governing the drainage dynamics.
authors: MMN, UMR CNRS Gulliver 7083, PSL research University, ESPCI ParisTech, 10 rue Vauquelin, F-75005 Paris, France.
authors: V
authors: V
authors: Miralles
authors: LOF, unité mixte Solvay-CNRS-Bordeaux 1, 178 avenue du Docteur Schweitzer, F-33608 Pessac cedex, France.
authors: B
authors: B
authors: Selva
authors: IPR, (UMR CNRS 6251), Université de Rennes 1, 35000 Rennes, France.
authors: I
authors: I
authors: Cantat
authors: MMN, UMR CNRS Gulliver 7083, PSL research University, ESPCI ParisTech, 10 rue Vauquelin, F-75005 Paris, France.
authors: M-C
authors: MC
authors: Jullien
mesh_terms: D000388:Air; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004867:Equipment Design; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods*; D008962:Models, Theoretical; D014867:Water / Q000737:chemistry
chemical_list: D004129:Dimethylpolysiloxanes; D014867:Water; C013830:baysilon