Advanced filtration membranes using chitosan and graphene oxide

Patent metadata

Field	Value
Publication number	US-10596525-B2
Application number	US-201715671043-A
Country	US
Kind code	B2
Filing date	Aug 7, 2017
Priority date	Aug 7, 2017
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A composition of five parts by mass of chitosan and one part graphene oxide is suspended in water. The composition may be used to form filtration layers of any size or shape and may be reinforced by additional layers. The composition may be used to construct a large filtration apparatus of any size or shape and may be used to form highly resilient, antimicrobial structures and surfaces for a variety of applications.

First claim

What is claimed is:

1. A method of making a highly-resilient fluid and gas apparatus comprised of the steps of:
protonating a quantity chitosan to create protonated chitosan;
mixing a quantity of granular graphene oxide with said protonated chitosan to create a solution; filling a molding structure with a quantity of said solution;
evaporating said solution on a surface to create a membrane having a target thickness; and placing said membrane between two layers; wherein said quantity of chitosan and said quantity of graphene have a ratio between 4:1 and 6:1; and wherein a target thickness ranges from 5 to 200 microns and a target flow rate of at least 1.5 LMH is achieved.

2. The method of claim 1 wherein said quantity of chitosan and said quantity of graphene have a 5:1 ratio.

3. The method of claim 1 in which the step of protonating includes the step of creating a homogeneous mixture by rendering the chitosan water soluble.

4. The method of claim 1 wherein said layers are cellulose layers.

5. The method of claim 1 wherein said layers are comprised a material selected from the group consisting of paper, glass wool and permeable plastic.

6. The method, of claim 1 wherein the step of protonating further includes combining said quantity of chitosan with an acid.

7. The method of claim 6 wherein said acid is selected from the group consisting of Acetic Acid, Malic Acid, Succinic Acid, Glycolic Acid, Oxalic Acid, Adipic Acid, Citric Acid, Formic Acid Carboxylic Acid, Sulfonic Acid, Muriatic Acid and Tannic Acid.

8. The method of claim 6 wherein said acid is organic.

9. The method of claim 1 which further includes placing two or more of said membranes in serial configuration to accomplish a multi-staged filtration process.

10. The method of claim 1 wherein a target rejection rate of at least 97.5% is achieved.

Assignees

• Us Army

Inventors

• Medina Victor F
• Griggs Christopher S
• Mattei-Sosa Jose
• Petery Brooke
• Gurtowski Luke

Classifications

• C02F1/441

  by reverse osmosis · CPC title

• B01D2325/04

  Characteristic thickness · CPC title

• B01D2323/30

  Cross-linking · CPC title

• B01D2319/06

  Use of membranes of different materials or properties within one module · CPC title

• C02F1/44

  by dialysis, osmosis or reverse osmosis {(general membrane separation processes B01D61/00, membrane modules B01D63/00, electrodialysis C02F1/4693, combination of membrane modules and bioreactors C02F3/1268)} · CPC title