title: Environmentally responsive particles: from superhydrophobic particle films to water-dispersible microspheres.
abstract: We describe the preparation, by precipitation copolymerization, of multifunctional divinylbenzene-co-pentafluorostyrene microspheres able to produce superhydrophobic surfaces or disperse in aqueous media upon annealing either in air or water, respectively. For that purpose, an amphiphilic block copolymer, polystyrene-b-poly(acrylic acid), was introduced in the initial feed composed of divinylbenzene and 2,3,4,5,6-pentafluorostyrene. As a result, fluorinated particles were obtained in which the diblock copolymer was encapsulated during the polymerization step. Upon annealing in dry air, the particles are completely hydrophobic and form superhydrophobic surfaces. On the contrary, annealing in water induces the reorientation of the PAA groups toward the particle interface, thus the particles can be dispersed in aqueous media. In addition, the presence of carboxylic acid groups at the particle interface permits us to switch the surface charge between negative and neutral depending on the environmental pH.
authors.affiliation: Laboratoire de Chimie des Polymères Organiques, CNRS, Université Bordeaux I, ENSCPB. 16, Avenue Pey Berland, 33607 Pessac Cedex, France. jrodriguez@ictp.csic.es
authors.forename: Juan
authors.initials: J
authors.lastname: Rodriguez-Hernandez
authors.forename: Alexandra
authors.initials: A
authors.lastname: Muñoz-Bonilla
authors.forename: Antoine
authors.initials: A
authors.lastname: Bousquet
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Ibarboure
authors.forename: Eric
authors.initials: E
authors.lastname: Papon
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D008863:Microspheres; D014867:Water / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D014867:Water; C006903:carbopol 940