FILTRATION APPARATUS CONTAINING GRAPHENE OXIDE MEMBRANE
Embodiments described herein relate generally to graphene oxide membranes for fluid filtration and more specifically to graphene oxide membranes having tunable permeability, rejection rate, and flux. Some embodiments of the graphene oxide membranes disclosed herein are characterized as having a flux of at least about 2.5×10 −4 gallons per square foot per day per psi with a 1 wt % lactose solution at room temperature, and a lactose rejection rate of at least 50% with a 1 wt % lactose solution.
1 - 20 . (canceled)
21 . A method, comprising:
at a filtration apparatus, receiving a solution including lignin, the filtration apparatus including a graphene oxide membrane including a plurality of graphene oxide sheets, each of the graphene oxide sheets from the plurality of graphene oxide sheets covalently coupled to an adjacent graphene oxide sheet via a chemical linker; and
contacting the solution at a temperature of at least 50° C. with the graphene oxide membrane such that a portion of the solution is rejected by the graphene oxide membrane,
wherein at least 50% of the lignin in the solution is rejected by the graphene oxide membrane.
22 . The method of claim 21 , wherein the solution is a black liquor solution.
23 . The method of claim 22 , wherein the graphene oxide membrane has a rejection rate of at least 75% on a total solids basis.
24 . The method of claim 21 , wherein the solution includes a solute, the solute including at least one of sodium sulfate, sodium carbonate, sodium hydrosulfide, sodium thiosulfate, or sodium hydroxide.
25 . The method of claim 24 , wherein the graphene oxide membrane rejects at least 50% of the solute.
26 . The method of claim 21 , wherein the solution has a pH of at least about 11.
27 . The method of claim 21 , wherein the chemical linker has a formula Ia-1:
wherein:
L 1 is selected from —NH—, —C(═O)—NH—, or absent;
L 2 is selected from —C(═O)—NH—(CH 2 ) n —, —(CH 2 ) 2 —O—(CH 2 ) n —, or —NH—(CH 2 ) n —;
n is 0-4; and
denotes a point of coupling with a carbon atom on a graphene oxide sheet.
28 . The method of claim 21 , wherein the chemical linker has a formula Ib:
wherein:
L 3 is selected from —C(═O)—NH—(CH 2 ) m —, —C(═O)—NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —, or —NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —;
A 2 is selected from aryl, heteroaryl, C 4 -C 10 heterocycloalkyl, C 4 -C 10 cycloalkyl, or C 4 -C 10 alkyl, wherein the aryl, heteroaryl, heterocycloalkyl, cycloalkyl, and alkyl can each be optionally substituted by one or more substituents selected from halo, C 1 -C 4 alkoxy, or C 1 -C 4 alkyl;
m is 0-4; and
denotes a point of coupling with a carbon atom on a graphene oxide sheet.
29 . The method of claim 21 , wherein the chemical linker has a Formula Ib-1:
wherein:
L 3 is selected from —C(═O)—NH—(CH 2 ) m —, —C(═O)—NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —, or —NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —;
m is 0-4; and
denotes a point of coupling with a carbon atom on a graphene oxide sheet.
30 . The method of claim 21 , wherein the filtration apparatus further comprises a support substrate, the support substrate having an average pore size of about 0.1 μm to about 5 μm.
31 . The method of claim 30 , wherein the support substrate includes a material selected from polypropylene, polystyrene, polyethylene, polyethylene oxide, polyethersulfone, polytetrafluoroethylene, polyvinylidene fluoride, polymethylmethacrylate, polydimethylsiloxane, polyester, cellulose, cellulose acetate, cellulose nitrate, polyacrylonitrile, glass fiber, quartz, alumina, silver, polycarbonate, nylon, aramid, or polyether ether ketone.
32 . The method of claim 30 , wherein the support substrate has a Young's modulus of at least about 0.5 GPa and the solution is contacted with graphene oxide membrane at a pressure of at least about 500 psi.
33 . A method, comprising:
at a filtration apparatus, receiving a black liquor solution, the filtration apparatus including a graphene oxide membrane including a plurality of graphene oxide sheets, each of the graphene oxide sheets from the plurality of graphene oxide sheets covalently coupled to an adjacent graphene oxide sheet via a chemical linker; and
contacting the black liquor solution with the graphene oxide membrane such that a portion of the black liquor solution is rejected by the graphene oxide membrane with a rejection rate of at least about 75% on a total solids basis.
34 . The method of claim 33 , wherein the black liquor solution includes at least 10 wt. % total dissolved solids.
35 . The method of claim 33 , wherein the black liquor solution is contacted with the graphene oxide membrane at a temperature of at least 50° C.
36 . The method of claim 33 , wherein the black liquor solution includes sodium sulfate, sodium carbonate, sodium hydrosulfide, sodium thiosulfate, sodium hydroxide, or a combination thereof.
37 . The method of claim 36 , wherein the graphene oxide membrane rejects at least 50% of sodium included in the black liquor solution.
38 . The method of claim 33 , wherein the chemical linker has a formula Ia-1:
wherein:
L 1 is selected from —NH—, —C(═O)—NH—, or absent;
L 2 is selected from —C(═O)—NH—(CH 2 ) n —, —(CH 2 ) 2 —O—(CH 2 ) n —, or —NH—(CH 2 ) n —;
n is 0-4; and
denotes a point of coupling with a carbon atom on a graphene oxide sheet.
39 . The method of claim 33 , wherein the chemical linker has a formula Ib:
wherein:
L 3 is selected from —C(═O)—NH—(CH 2 ) m —, —C(═O)—NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —, or —NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —;
A 2 is selected from aryl, heteroaryl, C 4 -C 10 heterocycloalkyl, C 4 -C 10 cycloalkyl, or C 4 -C 10 alkyl, wherein the aryl, heteroaryl, heterocycloalkyl, cycloalkyl, and alkyl can each be optionally substituted by one or more substituents selected from halo, C 1 -C 4 alkoxy, or C 1 -C 4 alkyl;
m is 0-4; and
denotes a point of coupling with a carbon atom on a graphene oxide sheet.
40 . The method of claim 33 , wherein the chemical linker has a Formula Ib-1:
wherein:
L 3 is selected from —C(═O)—NH—(CH 2 ) m —, —C(═O)—NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —, or —NH—C(═O)—(CH 3 ) 2 —S—(CH 2 ) m —;
m is 0-4; and
denotes a point of coupling with a carbon atom on a graphene oxide sheet.
41 . The method of claim 33 , wherein the filtration apparatus further comprises a support substrate, the support substrate having a root mean square surface roughness of less than about 3 μm.
42 . The method of claim 40 , wherein the support substrate has an average pore size of about 0.1 μm to about 5 μm.
43 . The method of claim 42 , wherein the support substrate includes a material selected from polypropylene, polystyrene, polyethylene, polyethylene oxide, polyethersulfone, polytetrafluoroethylene, polyvinylidene fluoride, polymethylmethacrylate, polydimethylsiloxane, polyester, cellulose, cellulose acetate, cellulose nitrate, polyacrylonitrile, glass fiber, quartz, alumina, silver, polycarbonate, nylon, aramid, or polyether ether ketone.