Highly porous fibrous network materials for gas filtration

Patent metadata

Field	Value
Publication number	US-10315155-B2
Application number	US-201515315431-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	Jun 4, 2014
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

Membranes are provided for filtering a gas, in some cases air. Membranes using a highly porous cellulose nano fibrous barrier layer with a highly porous (surface-charged) substrate can exhibit high flux, high retention, and low pressure drop in air filtration of toxic aromatic gases, fumes, bacteria, viruses, dusts, and particulate matters.

First claim

What is claimed is:

1. A membrane comprising:
at least a first substrate layer including a polyolefin modified with at least one ionic compound; and
at least a second layer including a three-dimensional network comprising a material selected from the group consisting of polysaccharide nanofibers, cellulose nanofibers, chitin nanofibers, chitosan nanofibers, polysaccharide nanofibrils, polysaccharide nanostrips, cellulose nanostrips, carbon nanofibers, carbon nanotubes, porous graphene nanosheets, porous graphene oxide nanosheets, bacterial cellulose, and combinations thereof.

2. The membrane of claim 1 , wherein the polyolefin is selected from the group consisting of polyethylenes, polypropylenes, ethylene-propylene copolymers, ultra-high molecular weight polyethylenes, high pressure low density polyethylenes, linear low density polyethylenes, linear medium density polyethylenes, high density polyethylenes, and modified polyethylenes.

3. The membrane of claim 1 , wherein the polyolefin comprises a polyethylene.

4. The membrane of claim 1 , wherein the at least one ionic compound includes a cation selected from the group consisting of imidazolium, pyridinium and isoquinolinium.

5. The membrane of claim 1 , wherein the at least one ionic compound is selected from the group consisting of 1-docosanyl-3-methylimidazolium and 1-docosanyl-3-methylimidazolium hexafluorophosphate.

6. The membrane of claim 1 , wherein the three-dimensional network is crosslinked with a crosslinking agent selected from the group consisting of glyoxal, epichlorohydrin, polyacrylic acid, polyvinylamine hydrochloride, glutaraldehyde, 1,4-butanediol diglycidyl ether, formaldehyde, glyoxylic acid, oxydisuccinic acid, citric acid, polyethylenimine, polyvinyl alcohol, trimesoyl chloride, maleic anhydride, phosphorus oxychloride, trimetaphosphate, linear mixed anhydrides of acetic and di- or tribasic carboxlic acids, vinyl sulfone, diepoxides, cyanuric chloride, aldehyde, acetaldehyde, acrolein, and combinations thereof.

7. The membrane of claim 1 , wherein the three-dimensional network comprises nanofibers having a diameter from about 3 nm to about 50 nm.

8. The membrane of claim 1 , wherein the three-dimensional network has a thickness from about 20 nm to about 5000 μm.

9. The membrane of claim 1 , wherein the membrane has a thickness from about 0.1 μm to about 10000 μm.

10. A process for filtering a gas by passing the gas through the membrane of claim 1 .

11. A method of producing a filtration membrane comprising:
contacting a porous substrate, including polyolefin with at least one ionic compound, to form a substrate; and
applying to the substrate a three-dimensional network including a material selected from the group consisting of polysaccharide nanofibers, cellulose nanofibers, chitin nanofibers, chitosan nanofibers, polysaccharide nanofibrils, polysaccharide nanostrips, cellulose nanostrips, carbon nanofibers, carbon nanotubes, porous graphene nanosheets, porous graphene oxide nanosheets, bacterial cellulose, and combinations thereof, to form the filtration membrane.

12. The method of claim 11 , wherein the polyolefin is selected from the group consisting of polyethylenes, polypropylenes, ethylene-propylene copolymers, ultra-high molecular weight polyethylenes, high pressure low density polyethylenes, linear low density polyethylenes, linear medium density polyethylenes, high density polyethylenes, and modified polyethylenes.

13. The method of claim 11 , wherein the polyolefin comprises a polyethylene.

14. The method of claim 11 , wherein the at least one ionic compound includes a cation selected from the group consisting of imidazolium, pyridinium and isoquinolinium.

15. The method of claim 11 , wherein the at least one ionic compound is selected from the group consisting of 1-docosanyl-3-methylimidazolium and 1-docosanyl-3-methylimidazolium hexafluorophosphate.

16. The method of claim 11 , further comprising cross-linking the three-dimensional network by contacting the three-dimensional network with a crosslinking agent selected from the group consisting of glyoxal, epichlorohydrin, polyacrylic acid, polyvinylamine hydrochloride, glutaraldehyde, 1,4-butanediol diglycidyl ether, formaldehyde, glyoxylic acid, oxydisuccinic acid, citric acid, polyethylenimine, polyvinyl alcohol, trimesoyl chloride, maleic anhydride, phosphorus oxychloride, trimetaphosphate, linear mixed anhydrides of acetic and di-or tribasic carboxlic acids, vinyl sulfone, diepoxides, cyanuric chloride, aldehyde, acetaldehyde, acrolein, and combinations thereof.

17. The method of claim 11 , wherein the three-dimensional network comprises nanofibers having a diameter from about 3 nm to about 50 nm.

18. The method of claim 11 , wherein the three-dimensional network has a thickness from about 20 nm to about 5000 μm.

19. The method of claim 11 , wherein the filtration membrane has a thickness from about 0.1 μm to about 10000 μm.

20. A process for filtering a gas by passing the gas through the filtration membrane produced by the method of claim 11 .

21. The membrane of claim 1 , wherein the at least one ionic compound includes an anion selected from the group consisting of bromide, tetrafluoroborate, hexafluorophosphate, and bis(perfluoroethylsulfonyl)imide.

22. The method of claim 11 , wherein the at least one ionic compound includes an anion selected from the group consisting of bromide, tetrafluoroborate, hexafluorophosphate, and bis(perfluoroethylsulfonyl)imide.

Assignees

• Univ New York State Res Found

Inventors

• Chu Benjamin
• Hsiao Benjamin S
• Ma Hongyang

Classifications

• B01D39/1692 Primary

  Other shaped material, e.g. perforated or porous sheets · CPC title

• B01D67/0006

  by chemical reactions (in-situ polymerisation, polycondensation, cross-linking or reaction for manufacturing composite membranes B01D69/125) · CPC title

• B01D2323/30

  Cross-linking · CPC title

• B01D69/12

  Composite membranes; Ultra-thin membranes · CPC title

• B01D53/228 Primary

  characterised by specific membranes · CPC title