Multiblock copolymer films, methods of making same, and uses thereof
A method for forming an isoporous graded film comprising multiblock copolymers and isoporous graded films. The films have a surface layer and a bulk layer. The surface layer can have at least 1×10 14 pores/m 2 and a pore size distribution (d max /d min )) of less than 3. The bulk layer has an asymmetric structure. The films can be used in filtration applications.
1. A polymeric isoporous graded film comprising:
a triblock copolymer having:
a first terminal block incorporating a hydrophobic polymer, wherein the first terminal block has a glass transition temperature (T g ) of 25° C. or less, and wherein the hydrophobic polymer is selected from the group consisting of poly(isoprene), poly(butadiene), poly(butylene), and poly(isobutylene);
a second terminal block comprising a hydrogen-bonding polymer selected from the group consisting of poly((4-vinyl)pyridine), poly((2-vinyl) pyridine), poly(ethylene oxide), a poly(methacrylate), poly(acrylic acid), and poly(hydroxystyrene), and
a hydrophobic block located between the first terminal block and the second terminal block, the hydrophobic block selected from the group consisting of a poly(styrene), polyethylene, polypropylene, polyvinyl chloride, and polytetrafluoroethylene,
wherein the film has a bulk layer having a thickness of from 5 microns to 500 microns and pores having a size of from 10 nm to 100 microns; and
wherein the film has a toughness of at least 5 GJ/m 3 .
2. The film of claim 1 , wherein the film has a surface layer having a thickness of from 20 nm to 500 nm.
3. The film of claim 1 , wherein the film has a hydraulic permeability of at least 700 L m −2 hr −1 bar −1 .
4. The film of claim 1 , wherein the film has a surface layer having a thickness of from 20 nm to 500 nm and a plurality of pores 5 nm to 100 nm in size.
5. The film of claim 4 , wherein the plurality of pores have a pore density of at least 1×10 14 pores/m 2 .
6. The film of claim 1 , wherein the bulk layer comprises an asymmetric structure.
7. The film of claim 1 , wherein the size of the pores in the surface layer have a pore size distribution of less than 3, wherein the pore size distribution is the ratio of the maximum pore diameter (d max ) to the minimum pore diameter (d min ).
8. The film of claim 1 , wherein the triblock copolymer has a PDI of from 1.0 to 2.0.
9. The film of claim 1 , wherein the second terminal block is a poly((4-vinyl)pyridine) block having a M n of from 1×10 3 to 1×10 6 g/mol and the hydrophobic block is a poly(styrene) block having a M n of from 1×10 3 to 1×10 6 g/mol.
10. The film of claim 1 , wherein the film further comprises a homopolymer or small molecule.
11. The film of claim 10 , wherein the molar ratio of triblock copolymer to homopolymer is from 1:0.05 to 1:10 or the molar ratio of triblock copolymer to small molecule is from 1:1 to 1:1000.
12. The film of claim 1 , wherein the triblock copolymer has a molecular weight ranging from 37.5 to 200 kg/mol.
13. The film of claim 1 , wherein the triblock copolymer has a first terminal block volume fraction ranging from 0.13 to 0.43.
14. The film of claim 1 , wherein the triblock copolymer has a hydrophobic block volume fraction ranging from 0.4 to 0.64.
15. The film of claim 1 , wherein the triblock copolymer has a second terminal block volume fraction ranging from 0.04 to 0.32.
16. The film of claim 1 , wherein the triblock copolymer has a polydispersity index (PDI) ranging from 1.02 to 1.32.
17. A device comprising the film of claim 1 .
18. The device of claim 17 , wherein the device is a filtration device.
19. The device of claim 18 , wherein the filtration device is a virus filtration device or a protein filtration device.
20. The device of claim 17 , wherein the triblock copolymer comprises a poly(isoprene-b-styrene-b-4-vinylpyridine) triblock copolymer.