(1) Presentation(s)
Lun. 26/06/2017 11:30 Salle RdC, Bâtiment 11, RdC TONG Penger (Department of Physics, Hong Kong University of Science and Technology, Hong Kong) Interfacial pinning, hysteresis and dynamics of a moving contact line (Matière Molle) Contact angle hysteresis (CAH), where the motion of a contact line between a liquid interface and a solid substrate is pinned by the physical roughness and/or chemical inhomogeneity on the solid surface, is an outstanding problem in interfacial dynamics and has been with us for many years. Despite of numerous efforts, one still has a poor understanding of CAH on many ambient solid surfaces of interest. The study of CAH is of fundamental interest for our general understanding of a common class of problems involving elastic dynamics in random force fields and also has immense practical applications in tertiary oil recovery, drag reduction, advanced materials and microfluidics. In this talk I will present our recent experimental efforts in developing an atomic force microscope (AFM) based hanging fiber probe for the study of contact line dissipation and pinning-depinning dynamics [1-3]. With this new technique, AFM is used as a force sensor to measure the speed-dependent capillary force hysteresis and relaxation of a moving contact line formed on a long vertical glass fiber of a few microns in diameter with one end glued onto a AFM cantilever and the other end in contact with a liquid-air interface. Applications of this technique to the study of contact line dissipation and wetting dynamics will be discussed. --------- Pour plus d'informations, merci de contacter Truzzolillo D. |