CO2-philic thin film composite membranes
Embodiments of the present disclosure describe a copolymer composition comprising a polyether-based copolymer, wherein the copolymer dissolves in one or more of an alcohol and alcohol-water mixture. Embodiments of the present disclosure describe a thin-film composite membrane comprising a porous support and a selective layer comprising a polyether-based copolymer, wherein the polyether-based copolymer dissolves in one or more of an alcohol and alcohol-water mixture. Embodiments of the present disclosure describe a method of capturing one or more chemical species comprising contacting a thin-film composite membrane with a fluid composition, wherein the fluid composition includes at least CO 2 and capturing CO 2 from the fluid composition. Embodiments of the present disclosure also describe methods of synthesizing copolymer compositions and methods of fabricating composite membranes.
1. A thin film composite membrane, comprising:
a porous polymer support selected from polyacrylonitrile, polysulfone, polyetherimide, and polyvinyl difluoride; and
a CO 2 -philic defect-free selective layer comprising a polyacrylonitrile-r-methacrylate polyethylene glycol (PAN-r-PEGMA) copolymer, wherein the selective layer is characterized by:
a thickness in the range of 1.2 μm to 1.5 μm; and
a molecular weight in the range of 40 to 60 kDa.
2. The membrane of claim 1 , wherein the porous support includes PAN.
3. The membrane of claim 1 , wherein a thickness of the porous support ranges from 150 μm to 200 μm.
4. The membrane of claim 1 , wherein the polyether-based copolymer is one or more of PAN-r-PEGMA40, PAN-r-PEGMA60, PAN-r-PEGMA64, and PAN-r-PEGMA67.
5. The membrane of claim 1 , wherein the membrane exhibits a gas permeability in an order of CO 2 >H 2 >CH 4 >O 2 >N 2 .
6. The membrane of claim 1 , wherein the membrane exhibits a selectivity of CO 2 /N 2 >CO 2 /CH 4 >CO 2 /H 2 .
7. A method of fabricating a thin-film composite membrane, comprising:
dissolving a polyacrylonitrile-r-methacrylate polyethylene glycol (PAN-r-PEGMA) copolymer in one or more of an alcohol and alcohol-water mixture to form a copolymer solution; and
immersing or partially immersing a porous polymer support in the copolymer solution to form, by dip-coating, a CO 2 -philic defect-free thin-film composite membrane.
8. The method of claim 7 , wherein the dissolving proceeds at a temperature of 80° C.
9. The membrane of claim 7 , wherein a concentration of the PAN-r-PEGMA copolymer in the copolymer solution ranges from 1 wt. % to 3 wt. %.
10. The membrane of claim 7 , wherein the alcohol-water mixture is an ethanol-water mixture.
11. The membrane of claim 7 , wherein a ratio of alcohol to water in the alcohol-water mixture is 7:3 w/w.
12. The method of claim 7 , wherein the porous support includes PAN.
13. A method of capturing one or more chemical species, comprising:
contacting a thin-film composite membrane comprising PAN-r-PEGMA with a fluid composition, wherein the fluid composition includes at least CO 2 , and
capturing CO 2 from the fluid composition.
14. The method according to claim 13 , wherein the fluid composition further includes one or more of H 2 , CH 4 , O 2 , and N 2 .