Thin film composite forward osmosis membranes with performance enhancing layers

Patent metadata

Field	Value
Publication number	US-2016236153-A1
Application number	US-201514623313-A
Country	US
Kind code	A1
Filing date	Feb 16, 2015
Priority date	Feb 16, 2015
Publication date	Aug 18, 2016
Grant date	—

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

1 . A thin film composite (TFC) forward osmosis (FO) membrane, comprising:
a porous support, wherein the pores in the support comprise surfaces having thereon a hydrophilic self-assembled monolayer; and an active layer on the support, wherein the active layer is sufficiently dense to remove an ionic species from a liquid.

2 . The TFC membrane of claim 1 , wherein the self-assembled monolayer comprises hydrophilic-functionalized star polymers and/or block copolymers.

3 . The TFC membrane of claim 1 , wherein the self-assembled monolayer comprises star polymers, and wherein the star polymers comprise hydrophilic arms.

4 . The TFC membrane of claim 2 , wherein the hydrophilic-functionalized star polymers are crosslinked.

5 . The TFC membrane of claim 1 , wherein the active layer comprises a cross-linked aromatic polyamide film.

6 . The TFC membrane of claim 1 , wherein the porous support comprises a polysulfone.

7 . The TFC membrane of claim 3 , wherein the hydrophilic arms of the star polymers comprise positively charged moieties, neutral hydrophilic moieties, negatively charged moieties, zwitterionic moieties, or combinations thereof.

8 . The TFC membrane of claim 7 , wherein the positively charged moiety is selected from ammonium ions and their neutral precursors.

9 . The TFC membrane of claim 7 , wherein the negatively charged moiety is selected from carboxylates, phosphates sulfonates, sulfinates, sulfonamides, and imides.

10 . The TFC membrane of claim 7 , wherein the neutral hydrophilic moiety is selected from the group consisting of zwitterions, hydroxylalkylesters, hydroxylakylamide, polyethlyene oxide (PEO), and combination of thereof.

11 . A process of modifying a TFC FO membrane with hydrophilic-functionalized star polymers, comprising:
exposing a porous support to an aqueous solution of hydrophilic-functionalized star polymers; and draining the excess star polymer solution.

12 . The process of claim 11 , wherein the porous support is exposed to the aqueous solution of the hydrophilic star polymer for about 1 minute to about 5 hours.

13 . The process of claim 11 , comprising air-drying the porous support after the draining step.

14 . The process of claim 11 , comprising rinsing the porous support layer with deionized water after the draining step.

15 . A thin film composite (TFC) membrane, comprising:
a porous support, wherein at least some of the pores in the support comprise surfaces having thereon a hydrophilic layer comprising functionalized star polymer; and an active layer on the support, wherein the active layer comprises a layer of a polyamide, a plurality of layers of a star polymer, and combinations thereof.

16 . The TFC membrane of claim 15 , wherein the star polymer in the hydrophilic layer comprises a nanogel core and at least one amino-functional arm attached to the nanogel core.

17 . The TFC membrane of claim 15 , wherein the hydrophilic layer comprises the star polymer of the formula below:

wherein, R0 is a homopolymer or random copolymer with monomeric units selected from the group consisting of alkyl, cycloalkyl, alkoxy and combinations thereof; R1 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.

18 . The TFC membrane of claim 15 , wherein the hydrophilic layer comprises a star polymer with a nanogel core to which at least one carboxyl-functional arm is attached.

19 . The TFC membrane of claim 15 , wherein the hydrophilic layer comprises the star polymer of the formula below:

wherein, R0 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, R1 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 Res Found

Inventors

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

Classifications

• B05D1/18

  performed by dipping · CPC title

• B01D67/0088

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

• B01D71/56

  Polyamides, e.g. polyester-amides · CPC title

• B01D71/82

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

• B01D2325/36

  Hydrophilic membranes · CPC title