title: Interfacial Assembly of Surfactant-Decorated Nanoparticles: On the Rheological Description of a Colloidal 2D Glass.
abstract: We address the rheology of assemblies of surfactant-decorated silica nanoparticles irreversibly adsorbed at the gas/liquid interface. Positively charged surfactant molecules (such as CTAB) bind to silica nanoparticle surfaces, and the resulting particle-surfactant complexes adsorb at gas/liquid interfaces. The surfactant molecules control the wettability of such decorated nanoparticles and their adsorption. The interparticle forces can be tuned by changing the surfactant concentration Cs. Increasing Cs, in addition to a decrease of the particles wettability, leads to an increase of the area fraction of particles at the interface. Oscillatory shear measurements (strain- and frequency-sweep) have been performed. Here, we explore the effect of the surfactant concentration Cs. At high enough Cs, the interface is highly packed, and an overall solidlike response is observed, with 2D glass properties.
authors.affiliation: †Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, U.K.
authors.forename: Armando
authors.initials: A
authors.lastname: Maestro
authors.affiliation: ‡Physics of Complex Fluids, Department of Science and Technology, University of Twente, PO Box 217, Enschede, The Netherlands.
authors.forename: Omkar S
authors.initials: OS
authors.lastname: Deshmukh
authors.affiliation: ‡Physics of Complex Fluids, Department of Science and Technology, University of Twente, PO Box 217, Enschede, The Netherlands.
authors.forename: Frieder
authors.initials: F
authors.lastname: Mugele
authors.affiliation: §Laboratoire de Physique des Solides, CNRS UMR 8502, Bat. 510, Universite Paris-Sud XI, 91405 Orsay, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Langevin