ZWITTERIONIC SULFONE POLYMER FLAT SHEET MEMBRANE

1 . A flat sheet membrane comprising a polymer comprising structural units of formula IB attached to structural units of formula II

wherein

R 1 and R 2 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring;

k is from 0 to 10;

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

R 4 is a bond, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring;

R 5 and R 6 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring; and

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

a, a′ and b are independently at each occurrence 0, 1, 2, 3, or 4;

and

m and n are each, independently, 0 or 1.

2 . The flat sheet membrane of claim 1 , wherein the polymer comprises structural units of formula VII:

wherein P+Q=1, P=0.30-0.50, Q=0.50-0.70.

3 . The flat sheet membrane of claim 2 , wherein the mole fraction of the zwitterion-functionalized structural units of formula IB in the polymer is in a range from about 30 mole percent to about 50 mole percent of the total moles of the units of formula IB and formula II.

4 . The flat sheet membrane of claim 1 , wherein the molecular weight of the polymer is in a range from about 10000 g/mol to about 80000 g/mol.

5 . A flat sheet membrane module comprising a plurality of flat sheet membranes of claim 1 .

6 . A flat sheet membrane module comprising a plurality of flat sheet membranes of claim 2 .

7 . A flat sheet membrane, comprising a blend of a first polymer comprising a sulfone polymer having zwitterionic functionality and a second polymer comprising a sulfone polymer.

8 . The flat sheet membrane of claim 7 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula IA or formula IB attached to structural units of formula II:

wherein

R 1 and R 2 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring;

k is from 0 to 10;

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

R 4 is a bond, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring;

R 5 and R 6 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring; and

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

a, a′ and b are independently at each occurrence 0, 1, 2, 3, or 4;

and

m and n are each, independently, 0 or 1.

9 . The flat sheet membrane of claim 7 , wherein the second polymer comprising a sulfone polymer comprises structural units having the structure of formula II, III IV, or V

wherein

R 5 and R 6 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring; and

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

a and b are independently at each occurrence 0, 1, 2, 3, or 4; and

m and n are each, independently, 0 or 1.

10 . The flat sheet membrane of claim 7 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula IA or formula IB attached to structural units of formula II:

wherein

R 1 and R 2 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring;

k is from 0 to 10;

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

R 4 is a bond, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring;

R 5 and R 6 are independently at each occurrence a hydrogen atom, a halogen atom, a nitro group, a C 1 -C 12 alkyl, a C 3 -C 12 cycloalkyl, or an aryl ring; and

Y′ and R′ are each, independently, hydrogen, C 1 -C 20 alkyl, or an aryl ring;

a, a′ and b are independently at each occurrence 0, 1, 2, 3, or 4;

m and n are each, independently, 0 or 1; and

wherein the second polymer comprising a sulfone polymer comprises structural units having the structure of formula II, IV, or V

11 . The flat sheet membrane of claim 10 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula VI:

wherein w is 0, 1, 2, or 3.

12 . The flat sheet membrane of claim 10 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula VII:

wherein P+Q=1, P=0.30-0.50, Q=0.50-0.70.

13 . The flat sheet membrane of claim 12 , wherein the mole fraction of the zwitterion-functionalized structural units of formula IB in the first polymer is in a range from about 30 mole percent to about 50 mole percent of the total moles of the units of formula IB and formula II.

14 . The flat sheet membrane of claim 7 , wherein the molecular weight of the first polymer comprising a sulfone polymer having zwitterionic functionality is in a range from about 10000 g/mol to about 80000 g/mol.

15 . The flat sheet membrane of claim 10 , wherein the second polymer comprising a sulfone polymer comprises a polysulfone comprising structural units of formula II.

16 . The flat sheet membrane of claim 10 , wherein the second polymer comprising a sulfone polymer comprises a polyphenyl sulfone comprising structural units of formula IV.

17 . The flat sheet membrane of claim 10 , wherein the second polymer comprising a sulfone polymer comprises a polyethersulfone comprising structural units of formula V.

18 . The flat sheet membrane of claim 7 , wherein the second polymer comprising a sulfone polymer is in an amount from about 0.5 weight % to about 5 weight % of the total weight of polymer in the membrane.

19 . The flat sheet membrane of claim 7 , wherein the molecular weight of the second polymer comprising a sulfone polymer is in a range from about 50000 g/mol to about 80000 g/mol.

20 . The flat sheet membrane of claim 10 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula IB attached to structural units of formula II, and the second polymer comprising a sulfone polymer comprises structural units of formula II

21 . The flat sheet membrane of claim 10 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula IB attached to structural units of formula II, and the second polymer comprising a sulfone polymer comprises structural units of formula IV

22 . The flat sheet membrane of claim 10 , wherein the first polymer comprising a sulfone polymer having zwitterionic functionality comprises structural units of formula IB attached to structural units of formula II, and the second polymer comprising a sulfone polymer comprises structural units of formula V

23 . A flat sheet membrane module comprising a plurality of flat sheet membranes of claim 20 .

24 . A flat sheet membrane module comprising a plurality of flat sheet membranes of claim 21 .

25 . A flat sheet membrane module comprising a plurality of flat sheet membranes of claim 22 .