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); and
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 surface layer having a thickness of from 20 nm to 500 nm and a plurality of pores 5 nm to 100 nm in size and a pore density of at least 1×10 14 pores/m 2 , and
wherein the film has a bulk layer having a thickness of from 5 microns to 500 microns, pores having a size of from 10 nm to 100 microns.
2. 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 ).
3. The film of claim 1 , wherein the triblock copolymer has a polydispersity index (PDI) of from 1.0 to 2.0.
4. 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.
5. The film of claim 1 , wherein the film further comprises a homopolymer or small molecule.
6. The film of claim 5 , 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.
7. The film of claim 1 , wherein the film further comprises at least one inorganic material, wherein the inorganic material is disposed on at least a portion of the film.
8. The film of claim 7 , wherein the inorganic material is a plurality of inorganic nanoparticles.
9. The film of claim 8 , wherein the inorganic nanoparticles are gold or silver nanoparticles.
10. The film of claim 1 , wherein the second terminal block is a poly(methacrylate).
11. The film of claim 1 , wherein the triblock copolymer has a molecular weight ranging from 37.5 to 200 kg/mol.
12. The film of claim 1 , wherein the triblock copolymer has a first terminal block volume fraction ranging from 0.13 to 0.43, a hydrophobic block volume fraction ranging from 0.4 to 0.64, and a second terminal block volume fraction ranging from 0.04 to 0.32.
13. The film of claim 1 , wherein the triblock copolymer has a polydispersity index (PDI) ranging from 1.02 to 1.32.
14. The film of claim 1 , wherein the pores of the surface layer exhibit a square packed lattice.
15. The film of claim 1 , wherein the bulk layer has an asymmetric structure.
16. A device comprising the film of claim 1 .
17. The device of claim 16 , wherein the device is a filtration device.
18. The device of claim 17 , wherein the filtration device is a virus filtration device or a protein filtration device.
19. A polymeric isoporous graded film comprising a poly(isoprene-b-styrene-b-4-vinylpyridine) triblock copolymer, wherein
the triblock copolymer exhibits one or both of a polydispersity index (PDI) ranging from 1.02 to 1.32 and a molecular weight ranging from 37.5 to 166.8 kg/mol,
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 and a pore density of at least 1×10 14 pores/m 2 , and
the film has a bulk layer having a thickness of from 5 microns to 500 microns, pores having a size of from 10 nm to 100 microns, and an asymmetric substructure.