title: Tuning the Receding Contact Angle on Hydrogels by Addition of Particles.
abstract: Control of the swelling, chemical functionalization, and adhesivity of hydrogels are finding new applications in a wide range of material systems. We investigate experimentally the effect of adsorbed particles on hydrogels on the depinning of contact lines. In our experiments, a water drop containing polystyrene microspheres is deposited on a swelling hydrogel, which leads to the drop absorption and particle deposition. Two regimes are observed: a decreasing drop height with a pinned contact line followed by a receding contact line. We show that increasing the particles concentration increases the duration of the first regime and significantly decreases the total absorption time. The adsorbed particles increase the pinning force at the contact line. Finally, we develop a method to measure the receding contact angle with the consideration of the hydrogel swelling.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University , Princeton, New Jersey 08544, United States.|Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, Université Paris Diderot , Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, Paris, France.
authors.forename: François
authors.initials: F
authors.lastname: Boulogne
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University , Princeton, New Jersey 08544, United States.|LIPhy, CNRS, and Université Grenoble Alpes, 140 Rue de la Physique, 38402 Saint-Martin-d'Hères, France.
authors.forename: François
authors.initials: F
authors.lastname: Ingremeau
authors.affiliation: Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS, Université Paris Diderot , Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Limat
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University , Princeton, New Jersey 08544, United States.
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone