| 초록 |
Gyroid structure, bicontinuous pattern is useful to apply for membranes and thermoelectric application. However, 3D isotropic gyroid structures from block copolymer cannot easily obtained from the thin film because of the surface and interfacial energy difference. Furthermore, polystylene-block-polydimethylsiloxane(PS-b-PDMS) block copolymer is one of the biggest difference of surface energy difference block copolymer (20.4 mN/m and 40.8 mN/m). We introduce the top coats for a neutral layer between PS and PDMS on BCP films and finally realized gyroid thin films within 200 nm thickness with solvent annealing process. For the control of neutrality, we used hydrolyzed poly(vinyl acetate) as a top coat and controlled the swelling ratio of PS-b-PDMS thin film. With this method, gyroid pattern with 20 nm of periodicity could be observed. This approach suggests a general method to obtain gyroid thin film and control the neutrality even with the extremely different surface energy BCPs. |
