Modified polyamide membrane
View Patent ↗A modified polyamide membrane and method for making and using the same. The present invention includes many embodiments including methods comprising contacting a polyamide membrane with certain modifiers, including but not limited to certain oxazoline and/or thiazoline-based compounds, derivatives and polymers thereof. In one embodiment, the surface of a polyamide membrane is coated with a solution including a polyoxazoline and optionally a polyalkylene oxide material, followed by optional heating. Preferred embodiments may exhibit improved performance, e.g. increased rejection of certain species, (e.g. sodium chloride and/or boric oxides such as boric acid or various borate salts), reduced fouling, improved antimicrobial properties, and/or improved storage stability.
1. A method of modifying a reverse osmosis or nano filtration polyamide membrane comprising the step of contacting the polyamide membrane with a material comprising a reaction product of poly(oxazoline) and at least one of: i) a poly(alkylene oxide) material and ii) a polyfunctional epoxide material.
2. The method of claim 1 comprising the step of applying a solution comprising the material of claim 1 to at least a surface portion of the polyamide membrane.
3. The method of claim 2 comprising the step of heating the polyamide membrane after the application of solution.
4. The method of claim 1 wherein the material comprises poly(2-ethyl-2-oxazoline).
5. The method of claim 1 comprising the step of contacting the polyamide membrane with a polyalkylene oxide material.
6. The method of claim 1 wherein the polyamide membrane is coated with an aqueous-based solution comprising a poly(oxazoline) and a polyalkylene oxide material.
7. The method of claim 1 wherein the polyamide membrane is contacted with a reaction product of a poly(oxazoline) and a polyalkylene oxide material.
8. The method of claim 1 wherein the polyamide membrane is contacted with a reaction product of a poly(oxazoline) and a polyfunctional epoxide material.
9. A reverse osmosis or nano filtration polyamide composite membrane comprising a microporous support and a thin film polyamide layer including a surface, wherein at least a portion of said surface comprises a coating comprising a polymer comprising a poly(oxazoline) wherein said poly(oxazoline) comprises a repeating unit represented by Formula (II):
wherein:
n is an integer from 2 to 20,000;
R 1 , R 2 , R 3 and R 4 are each the same or different and are independently selected from: hydrogen, halogen, an alkyl group having from 1 to 4 carbon atoms, and an aryl group;
Y is selected from oxygen and sulfur; and
Z is selected from a group resulting in said polymer having solubility parameter greater than about 18 J 1/2 cm −3/2 and
wherein said poly(oxazoline) comprises a repeating unit of alkylene oxide represented by Formula (III):
wherein X is a carbon atom or a chemical bond; and R 4 is selected from: hydrogen, alkyl group comprising 1 to 4 carbon atoms, hydroxyl group, and a hydroxylalkyl group having from 1 to 4 carbon atoms.
10. The membrane of claim 9 wherein at least 95 weight percent of said poly(oxazoline) comprises a repeating unit represented by Formula II, and equal to or less than about 5 weight percent of said copolymer comprises a repeating unit of alkylene oxide represented by Formula (III).
11. A reverse osmosis or nano filtration polyamide composite membrane comprising a microporous support and a thin film polyamide layer including a surface, wherein at least a portion of said surface comprises a coating comprising a reaction product of a polymer comprising a poly(oxazoline) and at least one of: i) a poly(alkylene oxide) material and ii) a polyfunctional epoxide material.
12. The membrane of claim 11 wherein said polymer comprises a reaction product of a poly(oxazoline) and a poly(alkylene oxide).
13. The membrane of claim 11 wherein said polymer comprises a reaction product of a poly(oxazoline) and a polyfunctional epoxide.
14. The membrane of claim 11 wherein said coating comprises a polymer blend comprising poly(oxazoline) and poly(alkylene oxide).
15. The membrane of claim 11 wherein said poly(oxazoline) comprises a repeating unit represented by Formula (II):
wherein:
n is an integer from 2 to 20,000;
R 1 , R 2 , R 3 and R 4 are each the same or different and are independently selected from: hydrogen, halogen, an alkyl group having from 1 to 4 carbon atoms, and an aryl group;
Y is selected from oxygen and sulfur; and
Z is selected from a group resulting in said polymer having solubility parameter greater than about 18 J 1/2 cm −3/2 .
16. The membrane of claim 15 wherein R 1 , R 2 , R 3 and R 4 are each hydrogen; Y is oxygen; and n is an integer from 50 to 10,000.
17. The membrane of claim 15 wherein is Z is a solubilizing group.
18. The membrane of claim 15 wherein Z is an antimicrobial group.
19. The membrane of claim 15 wherein Z is selected from: hydrogen, an alkyl group having from 1 to 20 carbon atoms, an aryl group and a polyalkylene oxide group.
20. The membrane of claim 9 wherein R 1 , R 2 , R 3 and R 4 are each hydrogen; Y is oxygen; and n is an integer from 50 to 10,000.
21. The membrane of claim 9 wherein is Z is a solubilizing group.
22. The membrane of claim 9 wherein Z is an antimicrobial group.
23. The membrane of claim 9 wherein Z is selected from: hydrogen, an alkyl group having from 1 to 20 carbon atoms, an aryl group and a polyalkylene oxide group.