Thin film composite forward osmosis membranes with performance enhancing layers

Patent metadata

Field	Value
Publication number	US-10654002-B2
Application number	US-201815984943-A
Country	US
Kind code	B2
Filing date	May 21, 2018
Priority date	Feb 16, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A thin film composite (TFC) forward osmosis (FO) membrane includes a porous support with surfaces having thereon a hydrophilic self-assembled monolayer. An active layer on the support is sufficiently dense to remove an ionic species from a liquid.

First claim

The invention claimed is:

1. A process of modifying a thin film composite (TFC) forward osmosis FO membrane comprising a porous support with a plurality of pores extending from one face to an opposite face thereof, and an active layer on the support, the method comprising:
exposing the porous support to an aqueous solution of hydrophilic-functionalized star polymers comprising a central core and at least 6 polymeric arms covalently attached to the central core; and
forming on surfaces of at least some of the pores of the porous support a hydrophilic self-assembled monolayer of the star polymers.

2. The process of claim 1 , further comprising drying the support.

3. The process of claim 2 , further comprising draining an excess of the aqueous solution of hydrophilic-functionalized star polymers prior to drying the support.

4. The process of claim 3 , comprising rinsing the support with water after the draining step.

5. The process of claim 2 , wherein the support is air-dried.

6. The process of claim 1 , wherein the support is exposed to the aqueous solution of the hydrophilic star polymer for about 1 minute to about 5 hours.

7. The process of claim 1 , wherein the star polymers comprise hydrophilic arms.

8. The process of claim 1 , wherein the hydrophilic-functionalized star polymers are crosslinked.

9. The process of claim 1 , wherein the active layer comprises a cross-linked aromatic polyamide film.

10. The process of claim 1 , wherein the support comprises a polysulfone.

11. The process of claim 7 , wherein the hydrophilic arms of the star polymers comprise positively charged moieties, neutral hydrophilic moieties, negatively charged moieties, zwitterionic moieties, or combinations thereof.

12. The process of claim 11 , wherein the positively charged moiety is chosen from ammonium ions and their neutral precursors.

13. The process of claim 11 , wherein the negatively charged moiety is selected from carboxylates, phosphates sulfonates, sulfinates, sulfonamides, and imides.

14. The process of claim 11 , wherein the neutral hydrophilic moiety is chosen from zwitterions, hydroxylalkylesters, hydroxylakylamide, polyethlyene oxide (PEO), and combinations thereof.

15. The process of claim 1 , wherein the core of the star polymers comprise a nanogel core, and wherein at least one amino-functional arm is attached to the nanogel core.

16. The process of claim 1 , wherein the monolayer comprises a star polymer of the formula below:

wherein, R 0 is a homopolymer or random copolymer with monomeric units selected from the group consisting of alkyl, cycloalkyl, alkoxy and combinations thereof; R 1 is selected from the group consisting of OCH 2 CH 2 OH and O—(PEG)-OCH 3 , with PEG representing poly(ethylene glycol); 0≤x≤1; k is greater than or equal to about 6; and n is greater than about 10.

17. The process of claim 1 , wherein the monolayer comprises a star polymer of the formula below:

wherein, R 0 is a homopolymer or a random copolymer with monomeric units selected from the group consisting of H, alkyl, cycloalkyl, alkoxy, and combinations thereof; k is greater than or equal to about 6, R 1 is selected from the group consisting of COOH, OCH 2 CH 2 OH, O—(PEG), wherein PEG represents poly(ethylene glycol), OCH 3 , N(CH 3 ) 2 , OCH 2 CH 2 N + (CH 3 ) 2 (CH 2 ) 3 SO 3 − , and combinations thereof; 0≤x≤1, and n is greater than about 10.

Assignees

• IBM
• San Jose State Univ Research Foundation

Inventors

• Dubois Geraud J
• Miller Robert D
• Na Young-Hye
• Piunova Victoria
• Sly Joseph
• Stillman Daniel

Classifications

• B01D71/82

  characterised by the presence of specified groups, e.g. introduced by chemical after-treatment · CPC title

• B05D1/18

  performed by dipping · CPC title

• B01D71/80

  Block polymers · CPC title

• B01D67/0088

  Physical treatment with compounds, e.g. swelling, coating or impregnation · CPC title

• B01D2323/30

  Cross-linking · CPC title