Separation membrane, method for preparing the same and unit for purification

Patent metadata

Field	Value
Publication number	US-9636640-B2
Application number	US-201314415625-A
Country	US
Kind code	B2
Filing date	Sep 27, 2013
Priority date	Sep 28, 2012
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A separation membrane for removing contaminants comprises: a hydrophobic membrane; and a graphene oxide layer formed to cover the hydrophobic membrane partially or wholly, wherein one surface of the hydrophobic membrane facing the graphene oxide layer has been hydrophilic-processed. The separation membrane is capable of enhancing removal efficiency on volatile contaminants, while maintaining a performance of the conventional separation membrane. The separation membrane is useful as a separation membrane for water treatment. Further, the separation membrane may be comprised in a membrane distillation apparatus, or may be utilized as a filter of a humidifier or a water purifier.

First claim

The invention claimed is:

1. A method for preparing a separation membrane for removing contaminants, the method comprising:
a hydrophilic-processing step of preparing a hydrophobic membrane having one hydrophilic-processed surface; and
a graphene oxide layer forming step of forming a graphene oxide layer by applying a graphene oxide coating liquid containing graphene oxide particles onto the hydrophilic-processed surface of the hydrophobic membrane.

2. The method of claim 1 , wherein the hydrophilic-processing step comprises a process of forming a hydrophilic-processed layer by applying a hydrophilic coating liquid containing a hydrophilic polymer, onto the hydrophobic membrane.

3. The method of claim 2 , wherein at least one of a process of forming a graphene oxide layer by applying a graphene oxide coating liquid onto the hydrophilic-processed hydrophobic membrane, and a process of forming a hydrophilic-processed layer by applying a hydrophilic coating liquid onto the hydrophobic membrane is performed by a micro spray method selected from a group consisting of an air brush, a nebulizer, an atomizer, an electro-spray and combinations thereof.

4. The method of claim 1 , wherein at least one of the hydrophilic-processing step, and the graphene oxide layer forming step is performed in a state where a temperature of the hydrophobic membrane is 20° C.˜50° C.

5. The method of claim 1 , wherein the graphene oxide coating liquid comprises a solvent and graphene oxide particles, and wherein the solvent comprises one selected from a group consisting of water, ethylene glycol, dimethylformamide (DMF), methylpyrrolidone (NMP) tetrahydrofuran (THF) and combinations thereof.

Assignees

• Lg Electronics Inc

Inventors

• Oh Byungsoo
• Kye Jeongil
• Kim Minjoung

Classifications

• B01D67/0002

  Organic membrane manufacture · CPC title

• F24F6/00

  Air-humidification {, e.g. cooling by humidification} · CPC title

• F24F2003/1435

  comprising semi-permeable membrane · CPC title

• F24F6/14

  using nozzles · CPC title

• B01D2325/38

  Hydrophobic membranes · CPC title