PH sensitive hierarchically self-organized bioinspired films

P. Escalé , Laurent Rubatat (1) , Christophe Derail (1) , Maud Save (1) , Laurent Billon (1)

1 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux

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. Smart surface based on self-assembly of amphiphilic polystyrene-block-poly(4-vinylpyridine) diblock copolymer into hierarchically ordered honeycomb and micro-pillarded films exhibit reversible pH-responsive wettability.

Domaines: Physique [physics]

P. Escalé, Laurent Rubatat, Christophe Derail, Maud Save, Laurent Billon. PH sensitive hierarchically self-organized bioinspired films. Macromolecular Rapid Communications, 2011, 32 (14), pp.1072-1076. ⟨10.1002/marc.201100296⟩. ⟨hal-01560397⟩