| 초록 |
Inorganic membranes such as zeolite, sol-gels, and carbon membranes have many advantages over conventional polymeric membranes. Among the advantages, their excellent thermal and chemical stability can make it possible to endure their high permselectivity in harsh conditions and at an elevated temperature. In the present study, soluble polyimide was used as a precursor of carbon membrane for more reproducible and continuous process in the preparation. The polyimide was synthesized from dianhydride and diisocyanate monomers, and soluble to various aprotic solvents. In order to obtain high flux, the polyimide was prepared in the form of asymmetric structure that consisted of active skin layer and supported substrate, using the phase inversion technique. Then, the precursor membrane was converted into carbon membrane by inert pyrolysis at a given heating protocol. The pyrolysis protocol was predeterminated by using thermal gravimetric analyzer coupled with mass spectroscope (TGA-MS). In molecular probe study using small molecules such as He (2.60Å), CO2 (3.30Å), O2 (3.46Å), and N2 (3.64Å). The present carbon molecular sieve membranes derived from soluble polyimide showed a good molecular sieving capability without a significant loss of the permeability. |
