title: Surface wave excitations and backflow effect over dense polymer brushes.
abstract: Polymer brushes are being increasingly used to tailor surface physicochemistry for diverse applications such as wetting, adhesion of biological objects, implantable devices and much more. Here we perform Dissipative Particle Dynamics simulations to study the behaviour of dense polymer brushes under flow in a slit-pore channel. We discover that the system displays flow inversion at the brush interface for several disconnected ranges of the imposed flow. We associate such phenomenon to collective polymer dynamics: a wave propagating on the brush surface. The relation between the wavelength, the amplitude and the propagation speed of the flow-generated wave is consistent with the solution of the Stokes equations when an imposed traveling wave is assumed as the boundary condition (the famous Taylor's swimmer).
authors.affiliation: Université Grenoble Alpes/CNRS UMR 5588, LIPhy, 38041 Grenoble, France.|Dipartimento di Fisica, Sapienza-Universitá di Roma, Piazzale A. Moro 5, 00185 Roma, Italy.
authors.forename: Sofia
authors.initials: S
authors.lastname: Biagi
authors.affiliation: Dipartimento di Fisica, Sapienza-Universitá di Roma, Piazzale A. Moro 5, 00185 Roma, Italy.|Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rovigatti
authors.affiliation: Dipartimento di Fisica, Sapienza-Universitá di Roma, Piazzale A. Moro 5, 00185 Roma, Italy.|Istituto Sistemi Complessi (ISC), Via dei Taurini 19, 00185 Roma, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sciortino
authors.affiliation: Université Grenoble Alpes/CNRS UMR 5588, LIPhy, 38041 Grenoble, France.
authors.forename: Chaouqi
authors.initials: C
authors.lastname: Misbah