title: Interfacial Rheology of Hydrogen-Bonded Polymer Multilayers Assembled at Liquid Interfaces: Influence of Anchoring Energy and Hydrophobic Interactions.
abstract: We study the 2D rheological properties of hydrogen-bonded polymer multilayers assembled directly at dodecane-water and air-water interfaces using pendant drop/bubble dilation and the double-wall ring method for interfacial shear. We use poly(vinylpyrrolidone) (PVP) as a proton acceptor and a series of polyacrylic acids as proton donors. The PAA series of chains with varying hydrophobicity was fashioned from poly(acrylic acid), (PAA), polymethacrylic acid (PMAA), and a homemade hydrophobically modified polymer. The latter consisted of a PAA backbone covalently grafted with C12 moieties at 1% mol (referred to as PAA-1C12). Replacing PAA with the more hydrophobic PMAA provides a route for combining hydrogen bonding and hydrophobic interactions to increase the strength and/or the number of links connecting the polyacid chains to PVP. This systematic replacement allows for control of the ability of the monomer units inside the absorbed polymer layer to reorganize as the interface is sheared or compressed. Consequently, the interplay of hydrogen bonding and hydrophobic interactions leads to control of the resistance of the polymer multilayers to both shear and dilation. Using PAA-1C12 as the first layer improves the anchoring energy of a few monomers of the chain without changing the strength of the monomer-monomer contact in the complex layer. In this way, the layer does not resist shear but resists compression. This strategy provides the means for using hydrophobicity to control the interfacial dynamics of the complexes adsorbed at the interface of the bubbles and droplets that either elongate or buckle upon compression. Moreover, we demonstrate the pH responsiveness of these interfacial multilayers by adding aliquots of NaOH to the acidic water subphase surrounding the bubbles and droplets. Subsequent pH changes can eventually break the polymer complex, providing opportunities for encapsulation/release applications.
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Sciences et Ingénierie de la Matière Molle (SIMM), CNRS UMR 7615, 10 rue Vauquelin, F-75231 Paris cedex 05, France.|Sorbonne-Universités, UPMC Univ Paris 06, SIMM, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Le Tirilly
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Sciences et Ingénierie de la Matière Molle (SIMM), CNRS UMR 7615, 10 rue Vauquelin, F-75231 Paris cedex 05, France.|Sorbonne-Universités, UPMC Univ Paris 06, SIMM, 10 rue Vauquelin, F-75231 Paris cedex 05, France.|École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Laboratory Gulliver, CNRS UMR 7083, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Corentin
authors.initials: C
authors.lastname: Tregouët
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Laboratory Gulliver, CNRS UMR 7083, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Mathilde
authors.initials: M
authors.lastname: Reyssat
authors.affiliation: Givaudan France SAS - 55, rue de la voie des Bans - CS50024, F-95102 Argenteuil, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Bône
authors.affiliation: Givaudan France SAS - 55, rue de la voie des Bans - CS50024, F-95102 Argenteuil, France.
authors.forename: Cédric
authors.initials: C
authors.lastname: Geffroy
authors.affiliation: Department of Chemical Engineering, Stanford University , Stanford, California 94305-5025, United States.
authors.forename: Gerald
authors.initials: G
authors.lastname: Fuller
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Sciences et Ingénierie de la Matière Molle (SIMM), CNRS UMR 7615, 10 rue Vauquelin, F-75231 Paris cedex 05, France.|Sorbonne-Universités, UPMC Univ Paris 06, SIMM, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Nadège
authors.initials: N
authors.lastname: Pantoustier
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Sciences et Ingénierie de la Matière Molle (SIMM), CNRS UMR 7615, 10 rue Vauquelin, F-75231 Paris cedex 05, France.|Sorbonne-Universités, UPMC Univ Paris 06, SIMM, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Perrin
authors.affiliation: École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), PSL Research University, Sciences et Ingénierie de la Matière Molle (SIMM), CNRS UMR 7615, 10 rue Vauquelin, F-75231 Paris cedex 05, France.|Sorbonne-Universités, UPMC Univ Paris 06, SIMM, 10 rue Vauquelin, F-75231 Paris cedex 05, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Monteux