| 초록 |
Gas pressure effect on phase transitions of polystyrene-block-poly(n-pentyl methacrylate) copolymers (PS-b-PnPMA) was investigated by Fourier-transformed Infra-red spectroscopy, small angle neutron scattering (SANS) and birefringence. Depending on the applied gas types, the size of closed-loop consisting of both the lower disordered-to-ordered transition (LDOT) and the upper ordered-to-disordered transition (UODT) varied dramatically. The loop size of PS-b-PnPMA became bigger with increasing nitrogen gas pressure, whereas it became smaller for helium gas. Thus, nitrogen could not be considered as a true inert gas for PS and PnPMA under high temperatures and moderate pressure range (less than 100 bar), but helium became a true inert gas. These results are explained by the binding energy calculation. Acknowledgement: This work was supported by Creative Research Initiative Program supported by KOSEF |
