ZWITTERION-FUNCTIONALIZED COPOLYMER HOLLOW-FIBER MEMBRANES AND ASSOCIATED METHOD
A hollow-fiber membrane is presented. The hollow fiber membrane, includes a copolymer including sulfone structural units having a formula (I) and zwitterion-functionalized structural units having a formula (II). Method of making the hollow-fiber membrane is also presented.
1 . A hollow-fiber membrane, comprising:
a copolymer comprising sulfone structural units having a formula (I) and zwitterion-functionalized structural units having a formula (II):
wherein “a” and “b” are independently at each occurrence 0, 1, 2, 3, or 4;
“n” and “p” are independently 0 or 1;
“k” is in a range from 0 to 10;
R 1 and R 2 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical;
R 3 and R 5 are independently a hydrogen atom, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical;
R 4 is a bond, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical; and
wherein a mole fraction of the zwitterion-functionalized structural units in the copolymer is less than about 50 mole percent.
2 . The hollow-fiber membrane of claim 1 , wherein the mole fraction of the zwitterion-functionalized structural units in the copolymer is in a range from about 30 mole percent to about 50 mole percent.
3 . The hollow-fiber membrane of claim 1 , wherein the sulfone structural units have a formula (III):
wherein “a” is independently at each occurrence 0, 1, 2, 3, or 4; and
R 1 is independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical.
4 . The hollow-fiber membrane of claim 1 , wherein the zwitterion-functionalized structural structural units have a formula (IV):
wherein “b” is independently at each occurrence 0, 1, 2, 3, or 4;
“k” is a number in a range from 0 to 10;
“m” is a number in a range from 1 to 10;and
R 2 is independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical.
5 . The hollow-fiber membrane of claim 1 , wherein the copolymer further comprises structural units having a formula (V):
wherein “c” is independently at each occurrence 0, 1, 2, 3, or 4;
R 6 is independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical; and
R 7 is independently at each occurrence a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical.
6 . The hollow-fiber membrane of claim 1 , wherein the molecular weight of the copolymer is in a range from about 10000 g/mol to about 75000 g/mol.
7 . A hollow-fiber module comprising a plurality of hollow-fiber membranes of claim 1 .
8 . A hemodialysis or hemofiltration apparatus comprising the hollow-fiber module of claim 7 .
9 . A hollow-fiber membrane, comprising a copolymer comprising sulfone structural units having a formula (III) and zwitterion-functionalized structural units having a formula (IV):
wherein “a” and “b” are independently at each occurrence 0, 1, 2, 3, or 4;
“k” is a number in a range from 0 to 10;
“m” is a number in a range from 1 to 10;
R 1 and R 2 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical; and
wherein a mole fraction of the zwitterion-functionalized structural units in the copolymer is less than about 50 mole percent.
10 . The hollow-fiber membrane of claim 9 , wherein the mole fraction of the zwitterion-functionalized structural units in the copolymer is in a range from about 30 mole percent to about 50 mole percent.
11 . A hemodialysis or hemofiltration apparatus comprising a hollow-fiber module comprising a plurality of hollow-fiber membranes of claim 9 .
12 . A method of forming a hollow-fiber membrane, comprising:
(A) providing a casting solution comprising a copolymer and a solvent, wherein the copolymer comprises sulfone structural units having a formula (I) and zwitterion-functionalized structural units having a formula (II):
wherein “a” and “b” are independently at each occurrence 0, 1, 2, 3, or 4;
“n” and “p” are independently 0 or 1;
“k” is in a range from 0 to 10;
R 1 and R 2 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical;
R 3 and R 5 are independently a hydrogen atom, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical;
R 4 is a bond, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical; and
wherein a mole fraction of the zwitterion-functionalized structural units in the copolymer is less than about 50 mole percent; and
(B) extruding the casting solution through an annular channel to form the hollow-fiber membrane.
13 . The method of claim 12 , wherein the mole fraction of the zwitterion-functionalized structural units in the copolymer is in a range from about 30 mole percent to about 50 mole percent.
14 . The method of claim 12 , wherein the sulfone structural units have a formula (III):
wherein “a” is independently at each occurrence 0, 1, 2, 3, or 4; and
R 1 is independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical.
15 . The method of claim 12 , wherein the zwitterion-functionalized structural structural units have a formula (IV):
wherein “b” is independently at each occurrence 0, 1, 2, 3, or 4;
“k” is a number in a range from 0 to 10;
“m” is a number in a range from 1 to 10; and
R 2 is independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical.
16 . The method of claim 12 , wherein the copolymer further comprises structural units having a formula (V):
wherein “c” is independently at each occurrence 0, 1, 2, 3, or 4;
R 6 is independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical; and
R 7 is independently at each occurrence a C 1 -C 12 aliphatic radical, a C 3 -C 12 cycloaliphatic radical, or a C 3 -C 12 aromatic radical.
17 . The method of claim 12 , wherein the casting solution further comprises an additive selected from the group consisting of polymers, anti-solvents, alkali metal halides, and combinations thereof.
18 . The method of claim 12 , wherein the casting solution further comprises alkali metal bromide.
19 . The method of claim 12 , wherein the additive is present in the casting solution in an amount in a range from about 0.1 weight percent to about 30 weight percent.
20 . The method of claim 12 , wherein the copolymer is present in the casting solution in an amount in a range from about 10 weight percent to about 30 weight percent.