title: pH sensitive hierarchically self-organized bioinspired films.
abstract: In the present manuscript, we have demonstrated that hierarchically structured smart porous polymer films based on honeycomb-patterned surface can be elaborated from PS-b-P4VP pH-responsive block copolymer using the breath figure process. Despite the fast film formation by a bottom-up process, the copolymer nanostructuration was observed inside the walls of the honeycomb porous film. Atomic force microscopy (AFM), small angle X-ray and neutron scattering (SAXS and SANS) measurements were used to reveal both the hexagonal arrays formed by the pores at the micrometer length scale and the hexagonal copolymer self-assembly at the nanometer length scale. Contact angle (CA) measurements were used to point out the reversible pH-responsive wettability character of the surface. The PS-b-P4VP honeycomb film shows a contact angle variation of 20° between pH 9 and pH 3. An increase of the roughness was obtained with the pincushions hexagonal array enhancing the pH responsiveness of the polymer film with a switching CA gap of 75° when pH tuned from pH 9 to pH 3. This work presents the first report on honeycomb porous and pincushion films exhibiting a reversible pH-responsive character.
authors.affiliation: IPREM Equipe de Physique et Chimie des Polymères, UMR 5254 CNRS, Université de Pau et des Pays de l'Adour, Hélioparc, 2 Avenue du Président Angot, 64053 Pau Cedex, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Escalé
authors.forename: Laurent
authors.initials: L
authors.lastname: Rubatat
authors.forename: Christophe
authors.initials: C
authors.lastname: Derail
authors.forename: Maud
authors.initials: M
authors.lastname: Save
authors.forename: Laurent
authors.initials: L
authors.lastname: Billon
mesh_terms: D006863:Hydrogen-Ion Concentration; D049329:Nanostructures / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties; D017155:Wettability
chemical_list: D011137:Polystyrenes; D011145:Polyvinyls; C521882:poly(styrene)-block-poly(4-vinylpyrindine) diblock copolymer