# US 2018/0021499 A1 · Urea sequestration compositions and methods

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- Number: US 2018/0021499 A1
- Document ID: US20180021499A1
- Status: Published application
- Kind: A1
- Application number: 15/547,963
- Filed: 2016-02-01
- Published: 2018-01-25
- Earliest claimed: 2015-02-06
- Assignees: Cabot Corporation
- Applicants: Cabot Corporation
- Inventors: Michael J. Natan; Agathagelos Kyrlidis
- Web page: https://patentgrep.com/patent/US20180021499A1

## CPC

- A61M 1/1696: {with dialysate regeneration}
- A61M 1/3486: {Biological, chemical treatment, e.g. chemical precipitation; treatment by absorbents}
- A61M 1/3679: {by absorption (A61M1/3675 takes precedence)}
- B01D 15/08: Selective adsorption, e.g. chromatography
- B01J 20/20: comprising free carbon; comprising carbon obtained by carbonising processes
- B01J 20/205: {Carbon nanostructures, e.g. nanotubes, nanohorns, nanocones, nanoballs (carbon nanotubes per se C01B32/15)}
- B01J 20/28057: {Surface area, e.g. B.E.T specific surface area}
- C01B 32/182: Graphene
- C01B 32/198: Graphene oxide
- C01B 32/23: Oxidation
- C02F 1/281: {using inorganic sorbents}
- C02F 1/286: {using natural organic sorbents or derivatives thereof}
- C07C 275/02: Salts; Complexes; Addition compounds
- B01D 53/04: with stationary adsorbents {(B01D53/025 takes precedence)}
- B01D 2253/102: Carbon
- B01D 2253/306: Surface area, e.g. BET-specific surface
- B01D 2257/40: Nitrogen compounds
- B01J 2220/42: Materials comprising a mixture of inorganic materials (materials coated or impregnated on a carrier B01J20/32)
- C02F 1/283: {using coal, charred products, or inorganic mixtures containing them}
- C02F 2101/38: containing nitrogen
- C07C 273/16: Separation; Purification
- A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)}
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS

## Abstract

Graphene-based materials for sequestering urea from aqueous solutions are provided. The graphene-based materials include graphene aggregates as well as graphene oxides.

## Claims

### Claim 1

A method comprising:
contacting a fluid comprising urea with a mass of graphene-based material particles;
sorbing at least a portion of the urea into or onto the graphene-based material particles to produce a graphene-based material/urea complex; and
reducing the level of urea in the fluid wherein the amount of urea in the graphene-based material/urea complex is greater than 25 mg urea per gram of graphene-based material.

### Claim 2 (depends on 1)

The method of claim 1 wherein the fluid is selected from at least one of an aqueous fluid, water, whole blood, blood plasma, processed blood, preserved blood, serum, plasma, clotted blood, anti-clotted blood, centrifuged blood, hematocrit, biological filtrate, ultrafiltrate, dialysate, extracellular fluids, intracellular fluids, interstitial fluids, lymphatic fluids, transcellular fluids, urine, urine-derived fluids, agricultural runoff and sewage.

### Claim 3

(canceled)

### Claim 4 (depends on 1)

The method of claim 1 wherein the concentration of urea in the fluid is reduced by greater than 10 percent by weight.

### Claim 5 (depends on 1)

The method of claim 1 comprising agitating, stirring, shaking, sonicating, flowing, cooling and/or heating a suspension of the graphene-based material particles in the fluid.

### Claim 6 (depends on 1)

The method of claim 1, the method comprising flowing the fluid through a bed comprising graphene-based material particles.

### Claim 7 (depends on 1)

The method of claim 1 wherein the graphene-based material is graphene oxide having an atomic ratio of carbon to oxygen of from 20:1 to 1.5:1.

### Claim 8 (depends on 1)

The method of claim 1 wherein the graphene-based material is a graphene aggregate.

### Claim 9 (depends on 1)

The method of claim 1 comprising removing at least one non-urea component of the fluid with graphene-based materials, activated carbon and/or modified activated carbon.

### Claim at position 10

10-14. (canceled)

### Claim 15

A method comprising:
contacting a dialysate with graphene-based material, the dialysate comprising urea;
sorbing at least a portion of the urea on or in the graphene-based material to form a graphene-based material/urea complex;
reducing the concentration of urea in the dialysate by greater than 25%, wherein the graphene-based material/urea complex comprises at least 10% urea by weight.

### Claim 16 (depends on 15)

The method of claim 15 further comprising contacting the dialysate with activated carbon.

### Claim 17 (depends on 15)

The method of claim 15 wherein contacting the dialysate with graphene-based material is selected from dispersing graphene-based material particles in the dialysate, passing the dialysate through a bed comprising graphene-based material particles, passing the dialysate through a membrane comprising graphene-based material and passing the dialysate through a column comprising graphene-based material.

### Claim 18 (depends on 15)

The method of claim 15 wherein the graphene-based material is graphene aggregates or graphene oxide.

### Claim 19 (depends on 15)

The method of claim 15 wherein at least a portion of the graphene-based material/urea complex is formed through intercalation.

### Claim 20 (depends on 15)

The method of claim 15 further comprising removing urea from the graphene-based material/urea complex.

### Claim 21 (depends on 15)

The method of claim 15 wherein the method is used to purify a fluid derived from one or more tissues of a patient exhibiting kidney dysfunction.

### Claim at position 18

22-54. (canceled)