초록 |
In the field of membrane-based gas separation, it is no doubt that an ultimate goal is to develop ideal materials having high permeability and selectivity for gas mixtures. Here, we designed nano-porous organic polymer materials containing large and accessible surface area above 500 m2g-1 and micropores with dimensions in the range < 2 nm. Compared to conventional micro-porous polymers having high free volume or organic network polymers, the present nano-porous polymers show an excellent molecular sieving effect even for gas pairs with small molecules, as well as ultrapermeable characteristics in gas separation. The polybenzoxazoles(PBOs) were easily obtained from hydroxyl-group containing polyimide during simple thermal conversion process at 450 oC. In this study, the structure-gas transport behaviors of the PBO membranes will be discussed in terms of various polyimides as the precursors for the PBO. |