title: A liquid contact line receding on a soft gel surface: dip-coating geometry investigation.
abstract: We studied the dynamics of a liquid contact line receding on a hydrophobic soft gel (SBS-paraffin). In order to realize a well-defined geometry with an accurate control of velocity, a dip-coating setup was implemented. Provided that the elastic modulus is small enough, a significant deformation takes place near the contact line, which in turn drastically influences the wetting behaviour. Depending on the translation velocity of the substrate, the contact line exhibits different regimes of motions. Continuous motions are observed at high and low velocities, meanwhile two types of stick-slip motion - periodic and erratic - appear at intermediate velocities. We suggest that the observed transitions could be explained in terms of the competition between different frequencies, i.e., the frequency of the strain field variation induced by the contact line motion and the crossover frequency of the gel related to the material relaxation. Our results provide systematic views on how the wetting of liquid is modified by the rheological properties of a complex soft substrate.
authors.affiliation: Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, Université Paris Diderot, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kajiya
authors.forename: Philippe
authors.initials: P
authors.lastname: Brunet
authors.forename: Laurent
authors.initials: L
authors.lastname: Royon
authors.forename: Adrian
authors.initials: A
authors.lastname: Daerr
authors.forename: Mathieu
authors.initials: M
authors.lastname: Receveur
authors.forename: Laurent
authors.initials: L
authors.lastname: Limat