| 초록 |
Nanoporous membranes are important in size-selective separation of nano- and bio-materials, and others. In this regard, we studied a preparation method for nanoporous membranes having isotropic structures by utilizing self-segregating properties of poly(styrene)-block-poly(2-vinylpyridine) diblock copolymers. Hence, PS-b-P2VP copolymers were first dissolved in a mixture of DMF/THF at relatively high concentration (＞ 10 wt%) and were cast on substrates. Subsequently, the cast film was partially dried at either room temperature or elevated temperature, which was immersed into deionized water. Since water is a non-solvent for both PS and P2VP blocks, precipitation of PS-b-P2VP copolymers occur into solvent- and polymer-rich phases. The incompatibility between PS and P2VP blocks spontaneously induced the formation of nanopores in the membrane. Therefore, by adjusting the molecular weight of copolymers and preparation conditions, the pore dimensions in the polymer membranes were adjusted. |
