Biological functionalisation of nanoporous polymer membranes.
Fonctionnalisation Biologique de membranes polymères nanoporeuses.
Résumé
Poly (vinylidene fluoride) (beta-PVDF) nanoporous membranes were made by chemical revealing of tracks induced from swift heavy ions irradiation. Pore opening and radiican be varied in a controllable manner with the etching time. Nanopores size in nanometer scale (from 12 nm to 50 nm) appears to be linearly dependent to the etching time. It was then necessary to adapt the characterization tools to these membranes. Consequently, we resorted to the use of structural analysis methods (Scanning Electron Microscopy, Small Angle Neutron Scattering) and developed evaluation methods of the membranes transport properties like gas permeation and ionic diusion. Results obtained conrm the pores opening (break through) and the hydrophobicity of material, which we have modied with hydrophilic molecules. In this precise case, the grafting of acrylic acid was initiated by the radicals still remains after track-etching (called radio-grafting). This key result was obtained by a study of Electron Paramagnetic Resonance. The labelling of introduced chemical functionalities with fluorescent probes was a very effective mean to visualize very few amounts of molecules by confocal microscopy. The radiografting was found specically localized inside etched tracks. The protocol others the possibility to create a double functionality, the one localized inside the nanopores and the other on the surface of membranes. The modication of radio-grafting parameters (the acrylic acid concentration, solvent nature, use of transfer agent) and the chemical properties of the nanopore walls have a direct incidence on the transport properties. Key Words : PVDF-beta, track-etching, nanopores, radicals, radiografting, selective functionalisation, Small Angle Neutron Scattering, Confocal Laser Scanning Microscopy.
Domaines
Physique [physics]
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