title: Effective Interaction between Active Colloids and Fluid Interfaces Induced by Marangoni Flows.
abstract: We show theoretically that near a fluid-fluid interface a single active colloidal particle generating, e.g., chemicals or a temperature gradient experiences an effective force of hydrodynamic origin. This force is due to the fluid flow driven by Marangoni stresses induced by the activity of the particle; it decays very slowly with the distance from the interface, and can be attractive or repulsive depending on how the activity modifies the surface tension. We show that, for typical systems, this interaction can dominate the dynamics of the particle as compared to Brownian motion, dispersion forces, or self-phoretic effects. In the attractive case, the interaction promotes the self-assembly of particles into a crystal-like monolayer at the interface.
authors.affiliation: Física Teórica, Universidad de Sevilla, Apartado de Correos 1065, 41080 Sevilla, Spain.
authors.forename: Alvaro
authors.initials: A
authors.lastname: Domínguez
authors.affiliation: Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, 70569 Stuttgart, Germany.|IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Malgaretti
authors.affiliation: Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, 70569 Stuttgart, Germany.|IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany.
authors.forename: M N
authors.initials: MN
authors.lastname: Popescu
authors.affiliation: Max-Planck-Institut für Intelligente Systeme, Heisenbergstraße 3, 70569 Stuttgart, Germany.|IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Dietrich