High free volume membrane for gas separation
A gas separation membrane, methods of forming the membrane, and methods of using the membrane for gas separation are provided. An exemplary gas separation membrane includes a cellulosic matrix and a polymer of intrinsic microporosity (PIM). The PIM includes chains coupled by a heat-treating under vacuum.
1. A gas separation membrane, comprising:
a cellulosic matrix; and
a polymer of intrinsic microporosity (PIM), wherein the PIM comprises chains coupled by a heat-treating under vacuum.
2. The gas separation membrane of claim 1 , wherein the cellulosic matrix comprises cellulose acetate (CA).
3. The gas separation membrane of claim 1 , wherein the cellulosic matrix comprises cellulose acetate butyrate (CAB).
4. The gas separation membrane of claim 1 , wherein the PIM comprises PIM-1.
5. The gas separation membrane of claim 1 , wherein the PIM comprises triazine rings coupling PIM chains.
6. The gas separation membrane of claim 1 , comprising larger free volume spaces and smaller free volume spaces formed by the heat-treating under vacuum.
7. The gas separation membrane of claim 1 , comprising a CO 2 permeability that is at least 50% higher than the CO 2 permeability of a neat CA membrane.
8. The gas separation membrane of claim 1 , comprising a CO 2 /CH 4 mixed gas selectivity that is within +/−10% of a neat CA membrane.
9. The gas separation membrane of claim 1 , comprising an H 2 S permeability that is at least 50% higher than the H 2 S permeability of a neat CA membrane.
10. The gas separation membrane of claim 1 , comprising an H 2 S/CH 4 mixed gas selectivity that is within +/−10% of a neat CA membrane.
11. The gas separation membrane of claim 1 , comprising between about 2.5 wt. % PIM and about 40 wt. % PIM of an amount of a CA in the membrane.
12. The gas separation membrane of claim 1 , comprising between about 5 wt. % PIM and about 20 wt. % PIM of an amount of a CA in the membrane.