Water-treatment separation membrane comprising ionic exchangeable polymer layer and method for forming same

Patent metadata

Field	Value
Publication number	US-10279320-B2
Application number	US-201415021847-A
Country	US
Kind code	B2
Filing date	Sep 16, 2014
Priority date	Sep 16, 2013
Publication date	May 7, 2019
Grant date	May 7, 2019

Abstract

The present invention relates to a water treatment membrane including a support; and a polymer layer including a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group on the support, wherein the polymer layer has ion exchange capacity (IEC) of 0.02 meq/g to 2.4 meq/g, and to a water treatment module, which have excellent salt rejection and permeate flow properties.

First claim

The invention claimed is:

1. A water treatment membrane comprising:
a support; and
a polymer layer on the support, the polymer layer including a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group,
wherein:
the polymer layer has ion exchange capacity (IEC) of 0.02 meq/g to 2.4 meq/g;
the hydrophilic repeating unit has the following Chemical Formula 3:

wherein:
G in each repeating unit is a functional group selected from the group consisting of:

R 5 has an ion exchange functional group that is —SO 3 M, —CO 3 M or —PO 3 M where M is H, Na or K; and
the hydrophobic repeating unit has the following Chemical Formula 4:

wherein:
H in each repeating unit is a functional group selected from the group consisting of:

and
* in Chemical Formula 3 and 4 is a site at which repeating units are connected and no separate atoms or molecules are present at the site.

2. The water treatment membrane of claim 1 , wherein a molar ratio of the hydrophilic repeating unit and the hydrophobic repeating unit is 1:9 to 1:1.

3. The water treatment membrane of claim 1 , wherein the copolymer has a weight average molecular weight of 30,000 to 1,000,000.

4. The water treatment membrane of claim 1 , wherein the polymer layer has a thickness of 0.1 μm to 200 μm.

5. The water treatment membrane of claim 1 , which has initial salt rejection of 97% or greater, and initial permeate flow of 38 to 48 gallon/ft 2 ·day when a sodium chloride (NaCl) solution having a concentration of 32,000 ppm passes therethrough under a pressure of 800 psi.

6. The water treatment membrane of claim 1 comprising one or more active layers on the polymer layer.

7. The water treatment membrane of claim 1 , which is a microfiltration membrane, an ultrafiltration membrane, a nanofiltration membrane or a reverse osmosis membrane.

8. A water treatment module comprising the water treatment membrane of claim 1 .

9. A method for manufacturing a water treatment membrane comprising:
coating a support using a solution including a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group, and a solvent; and
carrying out phase transition by immersing the coated support in a non-solvent,
wherein:
the copolymer is a copolymer containing a hydrophobic repeating unit and a hydrophilic repeating unit including an ion exchange functional group,

wherein:
G is any one or more functional groups selected from the group consisting of the following functional groups:

R 5 has an ion exchange functional group that is —SO 3 M, —CO 3 M or —PO 3 M where M is H, Na or K; and
the hydrophobic repeating unit has the following Chemical Formula 4:

wherein:
H is any one or more functional groups selected from the group consisting of the following functional groups:

and
* in Chemical Formula 3 and 4 is a site at which repeating units are connected and no separate atoms or molecules are present at the site.

10. The method for manufacturing a water treatment membrane of claim 9 , wherein the non-solvent is selected from the group consisting of distilled water that is distilled once, distilled water that is distilled three times, alcohols, and a mixture thereof.

11. The water treatment membrane of claim 1 , wherein:
the hydrophilic repeating unit is:

and
the hydrophobic repeating unit is:

12. The method for manufacturing a water treatment membrane of claim 9 , wherein:
the hydrophilic repeating unit is:

and
the hydrophobic repeating unit is:

Assignees

• Lg Chemical Ltd

Inventors

• Kwon Hyejin
• Jeong Seungpyo
• Kim Taehyeong
• Han Joong Jin
• Shin Chong Kyu

Classifications

• B01D2323/02

  Hydrophilization · CPC title

• B01D2323/12

  Specific ratios of components used · CPC title

• B01D2323/04

  Hydrophobization · CPC title

• B01D71/76

  Macromolecular material not specifically provided for in a single one of groups B01D71/08 - B01D71/74 (rubbers in general B01D71/24) · CPC title

• B01D61/145

  Ultrafiltration · CPC title