| 초록 |
We introduce a new and simple process, Corona Discharge Coating (CDC) to fabricate a thin polymer film. Directional corona discharge generated between a needle and a bottom plate under high electric field (5~10kV/cm) forms a smooth and flat thin film in large area within a few seconds. The uniformity and roughness of the film by CDC is as good as that by spin coating. The microstructures of various immiscible blend thin films by CDC were, however, different from those prepared by spin coating. PS/PMMA and MEH-PPV/PMMA blends by CDC showed unique morphologies where the domain size of the minority phase was much smaller than that by spin coating. The size depends on the electric field applied and ranges from 30nm to 60nm. We also observed that CDC induced microstructure orientation in which the micro domains of the minority phase were dominantly aligned along the radial direction from the center of the film. The orientation was confirmed using a PS/PVP block copolymer. We found that spherical PVP microdomains were transformed into cylindrical ones under corona discharge and the cylindrical microdomains were oriented with their cylinder axis parallel to the radial direction. In particular, the MEH-PPV/PMMA blend is known useful for highly efficient PLED device due to both the hole-trapping ability of PMMA domains and the effective hole-electron recombination at the domain interfaces. Therefore, we expect that the increased interfacial areas in thin film prepared by CDC provide the efficient PLED performance. |
