title: Drying kinetics driven by the shape of the air/water interface in a capillary channel.
abstract: We look at the drying process in a simple glass channel with dominant capillary effects as is the case in microfluidics. We find drying kinetics commonly observed for confined geometry, namely a constant period followed by a falling rate period. From visualization of the air/water interface with high resolution, we observe that the drying rate decreases without a drying front progression although this is the usually accepted mechanism for confined geometries. We show with FEM that in our specific geometry the falling rate period is due to changes in the shape of the air-water interface at the free surface where most evaporation occurs. Our simulations show that the sensitivity of the drying rate to the shape of the first air-water interface from the sample free surface implies that slight changes of the wetting or pinning conditions can significantly modify the drying rate.
authors.affiliation: Laboratoire Navier, Université Paris-Est, Paris, France. emmanuel.keita@ifsttar.fr.|School of Engineering and Applied Sciences and Physics Department, Harvard University, Boston, USA. emmanuel.keita@ifsttar.fr.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Keita
authors.affiliation: School of Engineering and Applied Sciences and Physics Department, Harvard University, Boston, USA.
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Koehler
authors.affiliation: Laboratoire Navier, Université Paris-Est, Paris, France.
authors.forename: Paméla
authors.initials: P
authors.lastname: Faure
authors.affiliation: School of Engineering and Applied Sciences and Physics Department, Harvard University, Boston, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Weitz
authors.affiliation: Laboratoire Navier, Université Paris-Est, Paris, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Coussot
mesh_terms: D000388:Air; D020342:Finite Element Analysis; D007700:Kinetics; D055585:Physical Phenomena; D014867:Water; D017155:Wettability
chemical_list: D014867:Water
keywords: Topical Issue: Wetting and Drying: Physics and Pattern Formation