Fluoropolymers and membranes comprising fluoropolymers (II)
Disclosed are a copolymer, porous membranes made from the copolymer, and a method of treating fluids to remove metal ions using the porous membranes, for example, from fluids originating in the microelectronics industry, wherein the copolymer includes monomeric units I and II, wherein monomeric unit I is of the formula A-X—CH 2 —B, wherein A is Rf—(CH 2 )n, Rf is a perfluoro alkyl group of the formula CF 3 —(CF 2 ) x —, wherein x is 3-12, n is 1-6, X is O or S, and B is vinylphenyl, and monomeric unit II is vinylpyridine.
1. A porous membrane comprising a copolymer disposed on a porous polymeric support, wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PET, PPS, PPSU (polyphenyl sulfone), PTFE, PVF (polyvinyl fluoride), PCTFE (polychlorotrifluoroethylene), FEP (fluorinated ethylene-propylene), ETFE (polyethylenetetrafluoroethylene), ECTFE (poly ethylenechlorotrifluoroethylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane,
wherein the copolymer is a copolymer of monomeric units I and II,
wherein monomeric unit I is of the formula
wherein A is Rf—(CH 2 )n, Rf is a perfluoro alkyl group of the formula CF 3 —(CF 2 ) x —, wherein x is 3-12, n is 1-6, and X is S,
and monomeric unit II is vinylpyridine;
wherein the porous membrane has a critical wetting surface tension (CWST) of 23 dynes/cm or less.
2. The porous membrane of claim 1 , wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PET, PPS, PPSU (polyphenyl sulfone), PVDF, PVF (polyvinyl fluoride), FEP (fluorinated ethylene-propylene), ETFE (polyethylenetetrafluoroethylene), ECTFE (poly ethylenechlorotrifluoroethylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane.
3. A method of preparing a porous membrane according to claim 1 ,
the method comprising:
(i) dissolving the copolymer in a solvent to obtain a solution comprising the copolymer;
(ii) casting the solution from (i) to obtain a coating;
(iii) evaporating the solvent from the coating; and optionally
(iv) washing the coating to obtain the porous membrane.
4. A method of filtering a fluid, the method comprising passing the fluid through the porous membrane of claim 1 .
5. The porous membrane of claim 1 , wherein n=2.
6. The porous membrane of claim 1 , wherein x=4-8.
7. The porous membrane of claim 1 , wherein the vinylpyridine is 4-vinyl pyridine.
8. The porous membrane of claim 1 , wherein the copolymer is a block copolymer.
9. The porous membrane of claim 1 , wherein the copolymer is a random copolymer.
10. The porous membrane of claim 5 , wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PPS, PPSU (polyphenyl sulfone), PVF (polyvinyl fluoride), FEP (fluorinated ethylene-propylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane.
11. The porous membrane of claim 6 , wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PPS, PPSU (polyphenyl sulfone), PVF (polyvinyl fluoride), FEP (fluorinated ethylene-propylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane.
12. The porous membrane of claim 7 , wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PPS, PPSU (polyphenyl sulfone), PVF (polyvinyl fluoride), FEP (fluorinated ethylene-propylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane.
13. The porous membrane of claim 8 , wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PPS, PPSU (polyphenyl sulfone), PVF (polyvinyl fluoride), FEP (fluorinated ethylene-propylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane.
14. The porous membrane of claim 9 , wherein the porous polymeric support is selected from PVC/PAN, polysulfone, polyethersulfone, PPS, PPSU (polyphenyl sulfone), PVF (polyvinyl fluoride), FEP (fluorinated ethylene-propylene), PFPE (perfluoropolyether), PFSA (perfluorosulfonic acid), and perfluoropolyoxetane.