| 초록 |
Carbon nanotubes (CNT) are one of the preferred fillers for polymer composites due to their exceptional electrical and mechanical properties. In this work, we would like to present the detailed study on dewetting phenomena of polymer bilayers when the various amount of CNT fillers are introduced. Carbon nanotubes were dispersed in DMF solution and spun cast onto Si wafers together with monodisperse polymethylmethacrylate (PMMA) of Mw=64k. The thickness of the films was 177nm. The tube concentration was varied from 0.02 to 0.2 weight percent. Monodisperse polystyrene of Mw= 270k was spun cast onto glass slides and floated from DI water over the samples. The bilayers were then annealed at T=175 o C for various times. The dewetting of the samples was then observed with optical and atomic force microscopy. We found that the rate of dewetting decreased rapidly with CNT concentration. These results will be interpreted in terms of the change in thin film viscosity and possibly glass transition temperature. In order to determine the molecular interaction between the polymer chains and CNTs, we also performed the neutron reflectivity and secondary ion mass spectrometry, and detail analysis will be presented. Part of this work was supported by the Ministry of Science and Technology of Korea through Proton Accelerator User Program (No. M102KS010001-02K1901-01810). |
