HIGHLY HYDROPHILIC AND HIGHLY OLEOPHOBIC MEMBRANE FOR OIL-WATER SEPARATION

• US 20140048478A1
• Filed: 04/27/2012
• Published: 02/20/2014
• Est. Priority Date: 04/28/2011
• Status: Active Grant

• Current Assignee: National University of Singapore
• Original Assignee: National University of Singapore
• Inventors: Bai, Renbi, Zhu, Xiaoying
• Granted Patent: US 9,657,126 B2
• Time in Patent Office: Days
• US Class Current: 210/500.34
• CPC Class Codes: B01D 17/085 with membranes
• CPC Class Codes: B01D 69/087 Details relating to the spinning process
• CPC Class Codes: B01D 71/32 containing fluorine atoms
• CPC Class Codes: B01D 71/34 Polyvinylidene fluoride
• CPC Class Codes: B01D 71/40 Polymers of unsaturated acids or derivatives thereof, e.g. salts, amides, imides, nitriles, anhydrides, esters
• CPC Class Codes: B01D 71/401 Polymers based on the polymerisation of acrylic acid, e.g. polyacrylate
• CPC Class Codes: B01D 71/78 Graft polymers
• CPC Class Codes: B01D 71/82 characterised by the presence of specified groups, e.g. introduced by chemical after-treatment
• CPC Class Codes: C02F 1/40 Devices for separating or removing fatty or oily substances or similar floating material cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration
• CPC Class Codes: C02F 2101/32 Hydrocarbons, e.g. oil
• CPC Class Codes: C08F 220/1804 C4-(meth)acrylate, e.g. butyl (meth)acrylate, isobutyl (meth)acrylate or tert-butyl (meth)acrylate
• CPC Class Codes: C08F 259/08 on to polymers containing fluorine
• CPC Class Codes: C08L 2205/02 containing two or more polymers of the same C08L -group
• CPC Class Codes: C08L 27/16 Homopolymers or copolymers or vinylidene fluoride
• CPC Class Codes: C08L 51/003 grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds C08L51/04, C08L51/06 take precedence

Abstract

A polymeric membrane for separating oil from water has a pore size of 0.005 μm to 5 μm, a thickness of 50 μm to 1,000 μm, a water contact angle of 0° to 60°, an oil contact angle of 40° to 100°. The membrane contains a hydrophobic matrix polymer and a functional polymer that contains a hydrophobic backbone and side chains. The side chains each have an oleophobic terminal segment and a hydrophilic internal segment. The weight ratio of the matrix polymer to the functional polymer is 99:1 to 1:9. Also disclosed is a method of making the above described membrane.

Claims

1. A polymer of the following formula:

2. The polymer of claim 1, wherein m is 10 to 500, n is 5 to 500, x is 50 to 500, y is 1 to 100, x₁ is 5 to 50, and y₁ is 5 to 50.

3. The polymer of claim 2, wherein m is 10 to 20, n is 5 to 10, x is 90 to 100, y is 5 to 10, x₁ is 5 to 10, and y₁ is 5 to 10.

10. The membrane of claim 7, wherein the matrix polymer is polyvinylidene fluoride, and the functional polymer is the polymer of claim 1.

11. The membrane of claim 10, wherein the membrane has a pore size of 0.05 μ

m to 0.5 μ

m, a thickness of 100 μ

m to 500 μ

m, a water contact angle of 5°

to 55°

, an oil contact angle of 40°

to 95°

, and a weight ratio of the matrix polymer to the functional polymer of 95;

5 to 6;

4.

12. The membrane of claim 11, wherein the membrane has a pore size of 0.1 μ

m to 0.3 μ

m, a thickness of 250 μ

m to 350 μ

m, a water contact angle of 10°

to 50°

, an oil contact angle of 40°

to 90°

, and a weight ratio of the matrix polymer to the functional polymer of 9;

1 to 7;

3.

13. The membrane of claim 7, wherein the matrix polymer is polyvinylidene fluoride, and the functional polymer is the polymer of claim 2.

14. The membrane of claim 13, wherein the membrane has a pore size of 0.05 gm to 0.5 μ

m, a thickness of 100 μ

m to 500 μ

m, a water contact angle of 5°

to 55°

, an oil contact angle of 40°

to 95°

, and a weight ratio of the matrix polymer to the functional polymer of 95;

5 to 6;

4.

15. The membrane of claim 14, wherein the membrane has a pore size of 0.1 μ

m to 0.3 μ

m, a thickness of 250 μ

m to 350 μ

m, a water contact angle of 10°

to 50°

, an oil contact angle of 40°

to 90°

, and a weight ratio of the matrix polymer to the functional polymer of 9;

1 to 7;

3.

16. The membrane of claim 7, wherein the matrix polymer is polyvinylidene fluoride, and the functional polymer is the polymer of claim 3.

17. The membrane of claim 16, wherein the membrane has a pore size of 0.05 μ

m to 0.5 μ

m, a thickness of 100 μ

m to 500 μ

m, a water contact angle of 5°

to 55°

, an oil contact angle of 40°

to 95°

, and a weight ratio of the matrix polymer to the functional polymer of 95;

5 to 6;

4.

18. The membrane of claim 17, wherein the membrane has a pore size of 0.1 μ

m to 0.3 μ

m, a thickness of 250 μ

m to 350 μ

m, a water contact angle of 10°

to 50°

, an oil contact angle of 40°

to 90°

, and a weight ratio of the matrix polymer to the functional polymer of 9;

1 to 7;

3.

4. A polymeric membrane for separating oil from water, the membrane comprising:

a matrix polymer that is hydrophobic, and

a functional polymer that contains a hydrophobic backbone and side chains, the side chains each having an oleophobic terminal segment and a hydrophilic internal segment, wherein the membrane has a pore size of 0.005 μ

m to 5 μ

m, a thickness of 50 μ

m to 1,000 μ

m, a water contact angle of 0°

to 60°

, an oil contact angle of 40°

to 100°

, and a weight ratio of the matrix polymer to the functional polymer of 99;

1 to 1;

9.

5. The membrane of claim 4, wherein the membrane has a pore size of 0.05 μ

m to 0.5 μ

m, a thickness of 100 μ

m to 500 μ

m, a water contact angle of 5°

to 55°

, an oil contact angle of 40°

to 95°

, and a weight ratio of the matrix polymer to the functional polymer of 95;

5 to 6;

4.

6. The membrane of claim 5, wherein the membrane has a pore size of 0.1 μ

m to 0.3 μ

m, a thickness of 250 μ

m to 350 μ

m, a water contact angle of 10°

to 50°

, an oil contact angle of 40°

to 90°

, and a weight ratio of the matrix polymer to the functional polymer of 9;

1 to 7;

3.

7. The membrane of claim 4, wherein the matrix polymer is polyvinylidene fluoride, polytetrafluoroethylene, polycarbonate, polyethylene terephthalate, polypropelene, polyamide, or a combination thereof;

the backbone is polyvinylidine fluoride, polytetrafluoroethylene, polycarbonate, polyethylene terephthalate, polypropelene, polyamide, or a combination thereof;

the oleophobic terminal segment is a perfluoroalkyl group;

the hydrophilic internal segment is polyethylene glycol, poly(N-vinylpyrrolidone) group, polyacrylamidep, polyacrylacid, polystyrenesulfonate, or a combination thereof.

8. The membrane of claim 7, wherein the membrane has a pore size of 0.05 μ

m to 0.5 μ

m, a thickness of 100 μ

m to 500 μ

m, a water contact angle of 5°

to 55°

, an oil contact angle of 40°

to 95°

, and a weight ratio of the matrix polymer to the functional polymer of 95;

5 to 6;

4.

9. The membrane of claim 8, wherein the membrane has a pore size of 0.1 μ

m to 0.3 μ

m, a thickness of 250 μ

m to 350 μ

m, a water contact angle of 10°

to 50°

, an oil contact angle of 40°

to 90°

, and a weight ratio of the matrix polymer to the functional polymer of 9;

1 to 7;

3.

19. A method for making a polymeric membrane comprising:

dissolving a matrix polymer and a functional polymer in a blend solvent to obtain a blend solution,

degassing the blend solution to obtain a deaerated solution, and

immersing the deaerated solution into a coagulation liquid to form the polymeric membrane,

wherein the matrix polymer is hydrophobic and the functional polymer contains a hydrophobic backbone and hydrophilic side chains, the side chains each having an oleophobic terminal segment and a hydrophilic internal segment.

20. The method of claim 19, wherein the immersing step is performed by extruding the deareated solution into the coagulation liquid to form a hollow fiber membrane.