Composite membrane

Patent metadata

Field	Value
Publication number	US-9440196-B2
Application number	US-201314372339-A
Country	US
Kind code	B2
Filing date	Feb 12, 2013
Priority date	Feb 21, 2012
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A method of making a composite membrane comprising the steps of forming a discriminating layer upon a surface of a porous support by sequentially applying immiscible coating solutions upon the support, wherein one coating solution comprises a crosslinking agent and another coating solution comprises a block copolymer, and the block copolymer comprises sacrificial segments and durable segments including reactive pendent groups which react with the crosslinking agent and form a crosslinked matrix comprising micro-domains of the sacrificial segments, and removing at least a portion of the sacrificial segments to yield pores.

First claim

The invention claimed is:

1. A method of making a composite membrane comprising the steps of forming a discriminating layer having a thickness of less than 20 μm upon a surface of a porous support by sequentially applying immiscible coating solutions upon the support, wherein:
i) one coating solution comprises a crosslinking agent,
ii) one coating solution comprises a block copolymer, wherein the block copolymer comprises durable segments that include reactive pendent groups and sacrificial segments and wherein the weight ratio of durable to sacrificial segments is from 1:6 to 2:1,
iii) the reactive pendent groups react with the crosslinking agent to form a crosslinked matrix comprising micro-domains of the sacrificial segments, and
wherein said method comprises etching at least a portion of the sacrificial segments to yield pores having a mean flow pore size of from 0.1 to 0.001 μm.

2. The method of claim 1 wherein the crosslinking agent comprises a polyfunctional amine monomer.

3. The method of claim 1 wherein the sacrificial segments of the block copolymer comprise polylactic acid.

4. The method of claim 1 wherein the durable segments of the block copolymer comprise polystyrene.

5. The method of claim 1 wherein the reactive pendent groups of the block copolymer comprise at least one of: acyl halide, anhydride, epoxy and isocyanate.

6. The method of claim 1 wherein the discriminating layer comprises a crosslinked polyamide.

7. The method of claim 1 wherein the crosslinking agent includes a moiety selected from: isocyanates, alcohols, acids and amines.

Assignees

• Dow Global Technologies Llc

Inventors

• Moll David J
• Silvis H C

Classifications

• B01D69/125 Primary

  In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction · CPC title

• B01D71/80

  Block polymers · CPC title

• B01D2323/32

  Use of chain transfer agents or inhibitors · CPC title

• B01D2323/30

  Cross-linking · CPC title

• B01D2323/34

  Use of radiation · CPC title