Membrane comprising self-assembled block copolymer and process for producing the same by spray coating (IIc)

Patent metadata

Field	Value
Publication number	US-9604181-B2
Application number	US-201514645633-A
Country	US
Kind code	B2
Filing date	Mar 12, 2015
Priority date	May 30, 2014
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

Disclosed are membranes formed from self-assembling block copolymers, for example, a diblock copolymer of the formula (I):

wherein R 1 —R 4 , n, and m are as described herein, which find use in preparing nanoporous membranes. Embodiments of the membranes contain the block copolymer that self-assembles into a cylindrical morphology. Also disclosed is a method of preparing such membrane which involves spray coating a polymer solution containing the diblock copolymer to obtain a thin film, followed by annealing the thin film in a solvent vapor and/or soaking in a solvent or mixture of solvents to form a nanoporous membrane.

First claim

The invention claimed is:

1. A method of preparing a porous membrane comprising a block copolymer of the formula (I) or (II):

wherein:
R 1 is a C 1 -C 22 alkyl group optionally substituted with a substituent selected from halo, alkoxy, alkylcarbonyl, alkoxycarbonyl, amido, and nitro, or a C 3 -C 11 cycloalkyl group, optionally substituted with a substituent selected from alkyl, halo, alkoxy, alkylcarbonyl, alkoxycarbonyl, amido, and nitro;
R 2 is a C 6 -C 20 aryl group or a heteroaryl group, optionally substituted with a substituent selected from hydroxy, amino, halo, alkoxy, alkylcarbonyl, alkoxycarbonyl, amido, and nitro;
one of R 3 and R 4 is a C 6 -C 14 aryl group, optionally substituted with a substituent selected from hydroxy, halo, amino, and nitro, and the other of R 3 and R 4 is a C 1 -C 22 alkoxy group, optionally substituted with a substituent selected from carboxy, amino, mercapto, alkynyl, alkenyl, halo, azido, and heterocyclyl; and
n and m are independently about 10 to about 2000; x is 0.1 to n and y is 0.1 to m;
wherein the volume fraction of the monomeric unit bearing R 2 to that of the monomeric unit bearing R 1 in the block copolymer is about 2.3 to about 5.6:1;
wherein the porous membrane has cylindrical morphology;
the method comprising:
(i) dissolving the block copolymer in a solvent system to obtain a polymer solution;
(ii) spray coating the polymer solution onto a substrate;
(iii) annealing the coating obtained in (ii) in a vapor comprising a solvent or a mixture of solvents to obtain a self-assembled structure; and optionally
(iv) annealing or soaking the self-assembled structure obtained in (iii) in a solvent or mixture of solvents to obtain a porous membrane.

2. The method of claim 1 , wherein R 1 is a C 10 -C 18 alkyl group, optionally substituted with a substituent selected from halo, alkoxy, alkylcarbonyl, alkoxycarbonyl, amido, and nitro.

3. The method of claim 1 , wherein R 2 is a phenyl group, optionally substituted with a substituent selected from hydroxy, amino, halo, alkoxy, alkylcarbonyl, alkoxycarbonyl, amido, and nitro.

4. The method of claim 1 , wherein R 3 is phenyl.

5. The method of claim 1 , wherein R 4 is a C 1 -C 6 alkoxy group.

6. The method of claim 1 , wherein n is about 10 to about 200 and m is about 50 to about 2000.

7. The method of claim 6 , wherein n is about 83 to about 190 and m is about 675 to about 1525.

8. The method of claim 7 , wherein n is about 105 and m is about 870.

9. The method of claim 1 , wherein the diblock copolymer of formula (I) has the following structure:

10. The method of claim 1 , wherein the solvent system includes a solvent or a mixture of solvents selected from halogenated hydrocarbons, ethers, amides, and sulfoxides.

11. The method of claim 1 , wherein the solvent system includes a solvent or a mixture of solvents selected from dichloromethane, 1-chloropentane, chloroform, 1,1-dichloroethane, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, tetrahydrofuran, 1,3-dioxane, and 1,4-dioxane.

12. The method of claim 1 , wherein the polymer solution contains about 3 to about 8% by weight of the diblock copolymer.

13. The method of claim 1 , wherein the substrate is selected from glass, silicon wafer, metal plate, plastic film, woven or nonwoven fabric, and a plastic film coated on a glass substrate or on or a silicon wafer.

14. The method of claim 1 , wherein the substrate is porous.

15. The method of claim 1 , wherein the annealing is carried out in the presence of a solvent vapor comprising dichloromethane.

16. The method of claim 1 , wherein the annealing is carried out twice.

17. A porous membrane prepared by the method of claim 1 .

18. The porous membrane of claim 17 , which is a single layer membrane.

19. The porous membrane of claim 18 , which is a composite membrane comprising a first layer and a second layer, the first layer comprising the diblock copolymer and ordered pores in a cylindrical morphology and the second layer comprising a microporous support layer.

Assignees

• Pall Corp

Inventors

• Aamer Khaled Abdel-Hakim Helmy
• Singh Amarnauth
• Shi Selina

Classifications

• B01D67/0083

  Thermal after-treatment · CPC title

• B01D67/0018

  Thermally induced processes [TIPS] · CPC title

• C08G2261/1412

  Saturated aliphatic units · CPC title

• C08G61/12

  Macromolecular compounds containing atoms other than carbon in the main chain of the macromolecule · CPC title

• B01D2323/26

  Spraying processes · CPC title