ELECTRICAL ANISOTROPY OF HORIZONTALLY ORIENTED DIBLOCK COPOLYMERS

Well defined poly(styrene-block-2-vinylpyridine) diblock copolymers were prepared by sequential anionic addition. Films were fabricated by casting diblock copolymer solutions on a Teflon sheet or flat glass dish by varying the casting conditions. Morphological results of these ultrathin sections were obtained using a transmission electron microscope. The surface characterization of diblock copolymer films was carried out by X-ray photoelectron microscopy. Both surface and bulk morphologies of these diblock copolymer films (approximately 50 wt% polystyrene blocks) showed a tendency that alternating lamellar structures of two microphases were oriented with their interfaces parallel to the surface that has contact with air or the substrate. Semiconducting materials were obtained upon exposure of these diblock copolymer films to alkyl halide vapour. As a result, these materials showed electrical anisotropy with conductivity.