Carbon nanotube composite membrane

Patent metadata

Field	Value
Publication number	US-9403121-B2
Application number	US-201414566451-A
Country	US
Kind code	B2
Filing date	Dec 10, 2014
Priority date	Jun 6, 2013
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A composite membrane for separations includes a fabric with a non-woven array of intermingled carbon nanotubes, and a dopant incorporated with the fabric to form a non-porous, permeable composite. The composite membrane may be used to separate a target gas from a liquid by mounting the composite membrane in a housing chamber, and conditioning a permeate side of the chamber to establish a driving force for the target gas across the non-porous, permeable composite membrane.

First claim

What is claimed is:

1. A method for preparing a composite gas separation membrane for separating a gas-liquid mixture, said method comprising:
providing a fabric comprising a non-woven array of intermingled carbon nanotubes, wherein said non-woven array defines interstices between said intermingled carbon nanotubes;
providing a dopant in a liquid medium to form a dopant composition;
at least partially immersing said fabric in said dopant composition; and
sonicating said dopant composition with an ultrasonic transducer such that said dopant composition penetrates said fabric interstices to an extent sufficient to establish a nonporous but permeable composite structure with said fabric.

2. A method as in claim 1 wherein said nonporous composite structure exhibits a target gas permeance of at least 0.1 GPU.

3. A method as in claim 1 wherein said fabric has a density of between about 1-20 g/m 2 .

4. A method as in claim 1 wherein said dopant is present in said dopant composition at a concentration of between about 1-50 weight percent.

5. A method as in claim 4 , including heating said dopant composition to between 60-90° C.

6. A method as in claim 1 wherein said ultrasonic transducer emits sonic energy at a frequency of between about 10-50 KHz.

7. A composite gas-separation membrane, comprising:
a substrate body having first and second generally opposed surfaces defining a thickness therebetween, said body comprising a non-woven fabric of intermingled carbon nanotubes defining interstices between said intermingled carbon nanotubes; and
a polymer dopant distributed within the interstices and throughout said thickness to form a network that is sufficient to establish a non-porous but permeable barrier between said first and second surfaces.

8. A composite gas-separation membrane as in claim 7 wherein said polymer dopant is substantially uniformly distributed throughout said substrate body.

9. A method as in claim 1 wherein said dopant includes an amorphous fluoropolymer.

10. A method as in claim 9 wherein said liquid medium is a solvent for said amorphous fluoropolymer.

11. A method as in claim 1 , including heating said dopant composition prior to sonicating said dopant composition with said ultrasonic transducer.

12. A method as in claim 11 , including heating said dopant composition to a temperature at which said dopant composition exhibits a viscosity suitable to penetrate said fabric interstices.

13. A method as in claim 12 wherein said temperature is between about 60-90° C.

14. A method as in claim 12 , including removing said liquid medium from said fabric interstices, wherein said dopant remains incorporated with said fabric to establish said composite structure.

Assignees

• Idex Health & Science Llc

Inventors

• Sims Carl
• Liu Quan

Classifications

• B01D2325/24

  Mechanical properties, e.g. strength · CPC title

• B01D69/148

  Organic/inorganic mixed matrix membranes · CPC title

• B01D69/02

  characterised by their properties · CPC title

• B01D19/0031

  by filtration · CPC title

• B01D53/228 Primary

  characterised by specific membranes · CPC title