Self-assembled structure and membrane comprising block copolymer and process for producing the same by spin coating (IIIa)

Patent metadata

Field	Value
Publication number	US-9593218-B2
Application number	US-201414292580-A
Country	US
Kind code	B2
Filing date	May 30, 2014
Priority date	May 30, 2014
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

Disclosed are self-assembled structures formed from self-assembling diblock copolymers of the formula (I):

wherein R 1 -R 4 , n, and m are as described herein, which find use in preparing nanoporous membranes. In embodiments of the self-assembled structure, the block copolymer self-assembles into a cylindrical morphology. Also disclosed is a method of preparing such self-assembled structure which involves spin coating a polymer solution containing the diblock copolymer to obtain a thin film, followed by solvent annealing of the film. Further disclosed is a method of preparing porous membranes from the self-assembled structures.

First claim

The invention claimed is:

1. A method of preparing a self-assembled porous membrane comprising a diblock copolymer of the formula (I):

wherein:
R 1 is a poly(alkyleneoxide) group of the formula, —(CHR—CH 2 —O) p -R′, wherein p=2-6, R is H or methyl, and R′ is H, a C 1 -C 6 alkyl group, or a C 3 -C 11 cycloalkyl group;
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;
wherein the volume fraction of the monomer bearing R 2 to that of the monomer bearing R 1 in the block copolymer is about 3.5:1, and the membrane has a cylindrical morphology;

the method comprising:
(i) dissolving the diblock copolymer in a solvent system to obtain a polymer solution;
(ii) spin coating the polymer solution onto a substrate;
(iii) annealing the coating obtained in (ii) to obtain a self-assembled porous membrane; and optionally
(iv) washing the self-assembled porous membrane obtained in (iii).

2. The method of claim 1 , wherein R is H.

3. The method of claim 1 , wherein p is 3-6.

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

5. The method of claim 1 , wherein R′ is methyl.

6. 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.

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

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

9. The method of claim 1 , wherein n is about 30 to about 350 and m is about 150 to about 1775.

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

11. 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.

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

13. The method of claim 1 , wherein the polymer solution contains about 0.1 to about 2% by weight of the diblock copolymer.

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

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

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

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

18. The self-assembled porous membrane of claim 17 , wherein the diblock copolymer in the membrane has a cylindrical morphology perpendicular to the plane of the membrane and the membrane has pores whose diameters are in the range of about 40 to 60 nm and pores extend all the way down to film thickness and at a depth of about 50 nm.

19. The method of claim 1 , wherein the solvent system is a mixture of dimethylformamide (DMF) and tetrahydrofuran (THF), a mixture of dimethylacetamide (DMA) and THF, a mixture of dimethylsulfoxide (DMSO) and THF, a mixture of DMSO and 1-chloropentane, a mixture of N-methylpyrrolidone (NMP) and 1-chloropentane, a mixture of DMF and 1-chloropentane, a mixture of 1,3-dioxane and THF, a mixture of 1,4-dioxane and THF, or a mixture of 1,3- or 1,4 dioxane, DMF, and THF.

20. The method of claim 19 , wherein the solvent system is a 70/30 volume % mixture of DMF and THF or a 70/30 volume % mixture of DMA and 1-chloropentane.

Assignees

• Pall Corp

Inventors

• Aamer Khaled Abdel-Hakim Helmy
• Shi Selina

Classifications

• B01D71/62

  Polycondensates having nitrogen-containing heterocyclic rings in the main chain · CPC title

• C08G2261/3342

  derived from cycloolefins containing heteroatoms · CPC title

• B01D71/80

  Block polymers · CPC title

• B01D71/78 Primary

  Graft polymers · CPC title

• C08J9/00 Primary

  Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof (mechanical aspects of shaping of plastics or substances in a plastic state for the production of porous or cellular articles B29C) · CPC title