Patent
US 10,835,873Graphene oxide membranes and methods related thereto
Mainak Majumder
US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 10,835,873Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1: Photographs of stable dispersions of graphene oxide undergoing concentration by addition of hydrogel beads. 10
Figure 2: (a) Illustration of an embodiment of the coating process of the present invention; and (b) image of the discotic nematic colloidal phase.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 6: Flow profile schematic of velocity profile in doctor blade channel for: (A) channel flow, (B) couette flow and (C) total flow.
Figure 7:
Figure 8: Effect of GO concentration on uniformity and continuity of film. Photographs which show the top surface of the shear-aligned membranes cast from different concentrations of GO under the same conditions of applied shear rate. It can be seen that by increasing concentration of GO (which …
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 11: Photograph showing viscoelastic GO (-40 mg/m l); scale bar is 1 cm.
Figure 12: Photograph showing SAM. The red circle in the photograph identifies dewetting spots in the SAMs, which is eliminated when processed from liquid crystalline GO; scale bars are 1 cm.
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 14: Photograph of the gravure printing machine and (inset) images of 13 x 14 cm 2 GO membranes with different thicknesses.
Figure 15: Polarized light images of (a-c) SAM and (d-f) vacuum filtration membrane. The SAM and vacuum filtration membrane are made from the nematic 20 phase GO at-40 mg/m l and isotropic phase at-10 pg/m l, respectively. (a) and (d) are falsely coloured polarized light images, where the hue …
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 18: Height profiles of SAM; scale bar is 1 pm.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 24: Results of exclusion testing of a membrane formed according to an embodiment of the invention.
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 26: Photographs of the membrane before (1) and after filtration (2) of methyl red, and after the cleaning process (3) which shows regeneration of the parent- 25 membrane surface; scale bare is 1 cm.
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 30: The results of permeability tests conducted on a membrane formed according to an embodiment of the invention.
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
Figure 32: Demonstration of long-term viability, low fouling behaviour of the membranes during filtration of BSA and flux recovery after chemical cleaning.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for concentrating a stabilized solution of graphene oxide comprising a continuous phase and having an initial graphene and/or graphene oxide concentration, the method comprising: adding an absorbent material to the solution; and absorbing at least a portion of the continuous phase from the solution with the absorbent material to form a solution having a graphene oxide concentration that is greater than the initial graphene oxide concentration. Withdrawn
The method of claim 1, further comprising the step of separating the absorbent material and the solution after the absorbing step. Withdrawn
The method of claim 1, wherein the continuous phase is water. Withdrawn
The method of claim 1, wherein the final graphene oxide concentration is greater than 15 mg/L. Withdrawn
The method of claim 1, wherein the absorbing step is conducted for a time of up to 1 hour. Withdrawn
A method of forming an asymmetric graphene oxide membrane suitable for the separation of molecules with a molecular weight in the range of 200-800 Da in a membrane separation process, wherein the membrane is prepared by a method of forming a film of a stabilized solution of discotic nematic graphene oxide on a substrate surface, the method comprising: applying an amount of the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration of 16 mg/mL or greater to the substrate surface; drawing the solution through a rectangular channel defined by two opposing surfaces having a gap there between at a shear rate of from 1,000 to 10,000 per second determined according to the Navier-Stokes equation assuming that fluid flow is Newtonian, wherein a first opposing surface of the channel is the substrate surface; and forming a film of aligned discotic graphene oxide having a thickness corresponding to a length of the gap, wherein the substrate is a porous substrate selected from the group consisting of polymers, metals, and ceramics, having pore sizes in the range of from 20 nm to 1000 nm; and wherein a second opposing surface is an applicator surface of a coating apparatus selected from the group consisting of: a rod coater, a roll coater, a knife coater, a flexible applicator, a curtain coater, and a gravure coater; and the step of drawing the solution through the channel comprises moving the two opposing surfaces relative to one another. Currently amended
The method of claim 9, wherein the graphene oxide concentration is 20 mg/mL or greater. Previously presented
The method of claim 9, wherein the method further comprises treating the film to remove at least some functional groups that are present on the film. Previously presented
A graphene oxide film or a reduced graphene oxide film formed according to the method of claim 9. Withdrawn
The method of claim 9, wherein the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration concentrating a more dilute solution of the discotic solution with hydrogel beads and separating the of 16 mg/mL or greater is obtained by graphene oxide by mixing the more dilute hydrogel beads from the suspension. New
1 1.-15. Canceled
Canceled
A graphene oxide membrane comprising a graphene oxide layer on a support layer, the graphene oxide layer comprising aligned discotic graphene oxide particles. Withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
asymmetric graphene oxide membrane
Materials described outside the worked examples.
graphene oxide
absorbent material/hydrogel material
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
target graphene oxide concentration after concentration step | >15 mg/mL (preferably ≥20 mg/mL, more preferably ≥30 mg/mL, most preferably 40-60 mg/mL) mg/mL | graphene oxide |
molecular weight separation range of asymmetric graphene oxide membrane |
Related documents with shared materials, methods, properties, or citations.
GRAPHENE FIBER AND METHOD OF MANUFACTURING THE SAME
GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE FOR GAS SEPARATION, REDUCED GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE AND METHOD FOR MANUFACTURING THE SAME
Patent
Atlas literature
Patent
US 10,835,873Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1: Photographs of stable dispersions of graphene oxide undergoing concentration by addition of hydrogel beads. 10
Figure 2: (a) Illustration of an embodiment of the coating process of the present invention; and (b) image of the discotic nematic colloidal phase.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 6: Flow profile schematic of velocity profile in doctor blade channel for: (A) channel flow, (B) couette flow and (C) total flow.
Figure 7:
Figure 8: Effect of GO concentration on uniformity and continuity of film. Photographs which show the top surface of the shear-aligned membranes cast from different concentrations of GO under the same conditions of applied shear rate. It can be seen that by increasing concentration of GO (which …
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 11: Photograph showing viscoelastic GO (-40 mg/m l); scale bar is 1 cm.
Figure 12: Photograph showing SAM. The red circle in the photograph identifies dewetting spots in the SAMs, which is eliminated when processed from liquid crystalline GO; scale bars are 1 cm.
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 14: Photograph of the gravure printing machine and (inset) images of 13 x 14 cm 2 GO membranes with different thicknesses.
Figure 15: Polarized light images of (a-c) SAM and (d-f) vacuum filtration membrane. The SAM and vacuum filtration membrane are made from the nematic 20 phase GO at-40 mg/m l and isotropic phase at-10 pg/m l, respectively. (a) and (d) are falsely coloured polarized light images, where the hue …
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 18: Height profiles of SAM; scale bar is 1 pm.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 24: Results of exclusion testing of a membrane formed according to an embodiment of the invention.
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 26: Photographs of the membrane before (1) and after filtration (2) of methyl red, and after the cleaning process (3) which shows regeneration of the parent- 25 membrane surface; scale bare is 1 cm.
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 30: The results of permeability tests conducted on a membrane formed according to an embodiment of the invention.
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
Figure 32: Demonstration of long-term viability, low fouling behaviour of the membranes during filtration of BSA and flux recovery after chemical cleaning.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for concentrating a stabilized solution of graphene oxide comprising a continuous phase and having an initial graphene and/or graphene oxide concentration, the method comprising: adding an absorbent material to the solution; and absorbing at least a portion of the continuous phase from the solution with the absorbent material to form a solution having a graphene oxide concentration that is greater than the initial graphene oxide concentration. Withdrawn
The method of claim 1, further comprising the step of separating the absorbent material and the solution after the absorbing step. Withdrawn
The method of claim 1, wherein the continuous phase is water. Withdrawn
The method of claim 1, wherein the final graphene oxide concentration is greater than 15 mg/L. Withdrawn
The method of claim 1, wherein the absorbing step is conducted for a time of up to 1 hour. Withdrawn
A method of forming an asymmetric graphene oxide membrane suitable for the separation of molecules with a molecular weight in the range of 200-800 Da in a membrane separation process, wherein the membrane is prepared by a method of forming a film of a stabilized solution of discotic nematic graphene oxide on a substrate surface, the method comprising: applying an amount of the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration of 16 mg/mL or greater to the substrate surface; drawing the solution through a rectangular channel defined by two opposing surfaces having a gap there between at a shear rate of from 1,000 to 10,000 per second determined according to the Navier-Stokes equation assuming that fluid flow is Newtonian, wherein a first opposing surface of the channel is the substrate surface; and forming a film of aligned discotic graphene oxide having a thickness corresponding to a length of the gap, wherein the substrate is a porous substrate selected from the group consisting of polymers, metals, and ceramics, having pore sizes in the range of from 20 nm to 1000 nm; and wherein a second opposing surface is an applicator surface of a coating apparatus selected from the group consisting of: a rod coater, a roll coater, a knife coater, a flexible applicator, a curtain coater, and a gravure coater; and the step of drawing the solution through the channel comprises moving the two opposing surfaces relative to one another. Currently amended
The method of claim 9, wherein the graphene oxide concentration is 20 mg/mL or greater. Previously presented
The method of claim 9, wherein the method further comprises treating the film to remove at least some functional groups that are present on the film. Previously presented
A graphene oxide film or a reduced graphene oxide film formed according to the method of claim 9. Withdrawn
The method of claim 9, wherein the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration concentrating a more dilute solution of the discotic solution with hydrogel beads and separating the of 16 mg/mL or greater is obtained by graphene oxide by mixing the more dilute hydrogel beads from the suspension. New
1 1.-15. Canceled
Canceled
A graphene oxide membrane comprising a graphene oxide layer on a support layer, the graphene oxide layer comprising aligned discotic graphene oxide particles. Withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
asymmetric graphene oxide membrane
Materials described outside the worked examples.
graphene oxide
absorbent material/hydrogel material
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
target graphene oxide concentration after concentration step | >15 mg/mL (preferably ≥20 mg/mL, more preferably ≥30 mg/mL, most preferably 40-60 mg/mL) mg/mL | graphene oxide |
molecular weight separation range of asymmetric graphene oxide membrane |
Related documents with shared materials, methods, properties, or citations.
GRAPHENE FIBER AND METHOD OF MANUFACTURING THE SAME
GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE FOR GAS SEPARATION, REDUCED GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE AND METHOD FOR MANUFACTURING THE SAME
Patent
Atlas literature
Patent
US 10,835,873Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1: Photographs of stable dispersions of graphene oxide undergoing concentration by addition of hydrogel beads. 10
Figure 2: (a) Illustration of an embodiment of the coating process of the present invention; and (b) image of the discotic nematic colloidal phase.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 6: Flow profile schematic of velocity profile in doctor blade channel for: (A) channel flow, (B) couette flow and (C) total flow.
Figure 7:
Figure 8: Effect of GO concentration on uniformity and continuity of film. Photographs which show the top surface of the shear-aligned membranes cast from different concentrations of GO under the same conditions of applied shear rate. It can be seen that by increasing concentration of GO (which …
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 11: Photograph showing viscoelastic GO (-40 mg/m l); scale bar is 1 cm.
Figure 12: Photograph showing SAM. The red circle in the photograph identifies dewetting spots in the SAMs, which is eliminated when processed from liquid crystalline GO; scale bars are 1 cm.
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 14: Photograph of the gravure printing machine and (inset) images of 13 x 14 cm 2 GO membranes with different thicknesses.
Figure 15: Polarized light images of (a-c) SAM and (d-f) vacuum filtration membrane. The SAM and vacuum filtration membrane are made from the nematic 20 phase GO at-40 mg/m l and isotropic phase at-10 pg/m l, respectively. (a) and (d) are falsely coloured polarized light images, where the hue …
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 18: Height profiles of SAM; scale bar is 1 pm.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 24: Results of exclusion testing of a membrane formed according to an embodiment of the invention.
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 26: Photographs of the membrane before (1) and after filtration (2) of methyl red, and after the cleaning process (3) which shows regeneration of the parent- 25 membrane surface; scale bare is 1 cm.
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 30: The results of permeability tests conducted on a membrane formed according to an embodiment of the invention.
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
Figure 32: Demonstration of long-term viability, low fouling behaviour of the membranes during filtration of BSA and flux recovery after chemical cleaning.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for concentrating a stabilized solution of graphene oxide comprising a continuous phase and having an initial graphene and/or graphene oxide concentration, the method comprising: adding an absorbent material to the solution; and absorbing at least a portion of the continuous phase from the solution with the absorbent material to form a solution having a graphene oxide concentration that is greater than the initial graphene oxide concentration. Withdrawn
The method of claim 1, further comprising the step of separating the absorbent material and the solution after the absorbing step. Withdrawn
The method of claim 1, wherein the continuous phase is water. Withdrawn
The method of claim 1, wherein the final graphene oxide concentration is greater than 15 mg/L. Withdrawn
The method of claim 1, wherein the absorbing step is conducted for a time of up to 1 hour. Withdrawn
A method of forming an asymmetric graphene oxide membrane suitable for the separation of molecules with a molecular weight in the range of 200-800 Da in a membrane separation process, wherein the membrane is prepared by a method of forming a film of a stabilized solution of discotic nematic graphene oxide on a substrate surface, the method comprising: applying an amount of the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration of 16 mg/mL or greater to the substrate surface; drawing the solution through a rectangular channel defined by two opposing surfaces having a gap there between at a shear rate of from 1,000 to 10,000 per second determined according to the Navier-Stokes equation assuming that fluid flow is Newtonian, wherein a first opposing surface of the channel is the substrate surface; and forming a film of aligned discotic graphene oxide having a thickness corresponding to a length of the gap, wherein the substrate is a porous substrate selected from the group consisting of polymers, metals, and ceramics, having pore sizes in the range of from 20 nm to 1000 nm; and wherein a second opposing surface is an applicator surface of a coating apparatus selected from the group consisting of: a rod coater, a roll coater, a knife coater, a flexible applicator, a curtain coater, and a gravure coater; and the step of drawing the solution through the channel comprises moving the two opposing surfaces relative to one another. Currently amended
The method of claim 9, wherein the graphene oxide concentration is 20 mg/mL or greater. Previously presented
The method of claim 9, wherein the method further comprises treating the film to remove at least some functional groups that are present on the film. Previously presented
A graphene oxide film or a reduced graphene oxide film formed according to the method of claim 9. Withdrawn
The method of claim 9, wherein the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration concentrating a more dilute solution of the discotic solution with hydrogel beads and separating the of 16 mg/mL or greater is obtained by graphene oxide by mixing the more dilute hydrogel beads from the suspension. New
1 1.-15. Canceled
Canceled
A graphene oxide membrane comprising a graphene oxide layer on a support layer, the graphene oxide layer comprising aligned discotic graphene oxide particles. Withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
asymmetric graphene oxide membrane
Materials described outside the worked examples.
graphene oxide
absorbent material/hydrogel material
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
target graphene oxide concentration after concentration step | >15 mg/mL (preferably ≥20 mg/mL, more preferably ≥30 mg/mL, most preferably 40-60 mg/mL) mg/mL | graphene oxide |
molecular weight separation range of asymmetric graphene oxide membrane |
Related documents with shared materials, methods, properties, or citations.
GRAPHENE FIBER AND METHOD OF MANUFACTURING THE SAME
GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE FOR GAS SEPARATION, REDUCED GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE AND METHOD FOR MANUFACTURING THE SAME
Patent
Atlas literature
Patent
US 10,835,873Patent drawings and their descriptions. Click a drawing to enlarge it.
Figure 1: Photographs of stable dispersions of graphene oxide undergoing concentration by addition of hydrogel beads. 10
Figure 2: (a) Illustration of an embodiment of the coating process of the present invention; and (b) image of the discotic nematic colloidal phase.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 6: Flow profile schematic of velocity profile in doctor blade channel for: (A) channel flow, (B) couette flow and (C) total flow.
Figure 7:
Figure 8: Effect of GO concentration on uniformity and continuity of film. Photographs which show the top surface of the shear-aligned membranes cast from different concentrations of GO under the same conditions of applied shear rate. It can be seen that by increasing concentration of GO (which …
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 11: Photograph showing viscoelastic GO (-40 mg/m l); scale bar is 1 cm.
Figure 12: Photograph showing SAM. The red circle in the photograph identifies dewetting spots in the SAMs, which is eliminated when processed from liquid crystalline GO; scale bars are 1 cm.
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 14: Photograph of the gravure printing machine and (inset) images of 13 x 14 cm 2 GO membranes with different thicknesses.
Figure 15: Polarized light images of (a-c) SAM and (d-f) vacuum filtration membrane. The SAM and vacuum filtration membrane are made from the nematic 20 phase GO at-40 mg/m l and isotropic phase at-10 pg/m l, respectively. (a) and (d) are falsely coloured polarized light images, where the hue …
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 18: Height profiles of SAM; scale bar is 1 pm.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 24: Results of exclusion testing of a membrane formed according to an embodiment of the invention.
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 26: Photographs of the membrane before (1) and after filtration (2) of methyl red, and after the cleaning process (3) which shows regeneration of the parent- 25 membrane surface; scale bare is 1 cm.
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 30: The results of permeability tests conducted on a membrane formed according to an embodiment of the invention.
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
Figure 32: Demonstration of long-term viability, low fouling behaviour of the membranes during filtration of BSA and flux recovery after chemical cleaning.
Claims define the patent's legal scope. Independent claims stand alone; dependent claims (nested) narrow them. Click a claim to expand its dependents.
A method for concentrating a stabilized solution of graphene oxide comprising a continuous phase and having an initial graphene and/or graphene oxide concentration, the method comprising: adding an absorbent material to the solution; and absorbing at least a portion of the continuous phase from the solution with the absorbent material to form a solution having a graphene oxide concentration that is greater than the initial graphene oxide concentration. Withdrawn
The method of claim 1, further comprising the step of separating the absorbent material and the solution after the absorbing step. Withdrawn
The method of claim 1, wherein the continuous phase is water. Withdrawn
The method of claim 1, wherein the final graphene oxide concentration is greater than 15 mg/L. Withdrawn
The method of claim 1, wherein the absorbing step is conducted for a time of up to 1 hour. Withdrawn
A method of forming an asymmetric graphene oxide membrane suitable for the separation of molecules with a molecular weight in the range of 200-800 Da in a membrane separation process, wherein the membrane is prepared by a method of forming a film of a stabilized solution of discotic nematic graphene oxide on a substrate surface, the method comprising: applying an amount of the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration of 16 mg/mL or greater to the substrate surface; drawing the solution through a rectangular channel defined by two opposing surfaces having a gap there between at a shear rate of from 1,000 to 10,000 per second determined according to the Navier-Stokes equation assuming that fluid flow is Newtonian, wherein a first opposing surface of the channel is the substrate surface; and forming a film of aligned discotic graphene oxide having a thickness corresponding to a length of the gap, wherein the substrate is a porous substrate selected from the group consisting of polymers, metals, and ceramics, having pore sizes in the range of from 20 nm to 1000 nm; and wherein a second opposing surface is an applicator surface of a coating apparatus selected from the group consisting of: a rod coater, a roll coater, a knife coater, a flexible applicator, a curtain coater, and a gravure coater; and the step of drawing the solution through the channel comprises moving the two opposing surfaces relative to one another. Currently amended
The method of claim 9, wherein the graphene oxide concentration is 20 mg/mL or greater. Previously presented
The method of claim 9, wherein the method further comprises treating the film to remove at least some functional groups that are present on the film. Previously presented
A graphene oxide film or a reduced graphene oxide film formed according to the method of claim 9. Withdrawn
The method of claim 9, wherein the solution of discotic graphene oxide in a nematic crystalline state with a graphene oxide concentration concentrating a more dilute solution of the discotic solution with hydrogel beads and separating the of 16 mg/mL or greater is obtained by graphene oxide by mixing the more dilute hydrogel beads from the suspension. New
1 1.-15. Canceled
Canceled
A graphene oxide membrane comprising a graphene oxide layer on a support layer, the graphene oxide layer comprising aligned discotic graphene oxide particles. Withdrawn
Layer stacks claimed or described, ordered top of device to substrate.
asymmetric graphene oxide membrane
Materials described outside the worked examples.
graphene oxide
absorbent material/hydrogel material
Additional fabrication and treatment steps described in the patent.
Measurements and analyses referenced in the patent, with their drawing references.
Figure 3: Hydrogel bead Raman spectroscopy characterization. Raman spectrum of GO, the hydrogel bead swollen in GO solution and the hydrogel bead swollen in RO water. 15
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
target graphene oxide concentration after concentration step | >15 mg/mL (preferably ≥20 mg/mL, more preferably ≥30 mg/mL, most preferably 40-60 mg/mL) mg/mL | graphene oxide |
molecular weight separation range of asymmetric graphene oxide membrane |
Related documents with shared materials, methods, properties, or citations.
GRAPHENE FIBER AND METHOD OF MANUFACTURING THE SAME
GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE FOR GAS SEPARATION, REDUCED GRAPHENE OXIDE NANOCOMPOSITE MEMBRANE AND METHOD FOR MANUFACTURING THE SAME
hydrogel beads
discotic nematic graphene oxide
porous substrate
reduced graphene oxide
superabsorbent polymer (sodium polyacrylate)
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
discotic nematic graphene oxide |
pore size of porous substrate support | 20–1000 nm | porous substrate |
shear rate during film coating | 1000-10000 s⁻¹ | discotic nematic graphene oxide |
Thickness | 20–1000 nm | — |
Thickness | 10–40 nm | — |
Thickness | 0.000001 cm | — |
Thickness | 500–4000 cm | — |
Thickness | 1–1150 cm | — |
Duration | ≤ 5 seconds | — |
Pressure | ≤ 2 bar | — |
Pressure | 0.0005–0.05 Pa | — |
Pressure | 0.001–0.04 Pa | — |
Pressure | 0.0016–0.03 Pa | — |
Pressure | 10–15 bar | — |
Duration | ≤ 1 hour | — |
Pressure | ≥ 50 Pa | — |
Pressure | ≥ 65 Pa | — |
Pressure | ≥ 80 Pa | — |
Pressure | ≥ 60 Pa | — |
Pressure | ≥ 70 Pa | — |
Pressure | ≥ 140 Pa | — |
Pressure | ≥ 160 Pa | — |
Pressure | ≥ 250 Pa | — |
Pressure | ≥ 300 Pa | — |
hydrogel beads
discotic nematic graphene oxide
porous substrate
reduced graphene oxide
superabsorbent polymer (sodium polyacrylate)
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
discotic nematic graphene oxide |
pore size of porous substrate support | 20–1000 nm | porous substrate |
shear rate during film coating | 1000-10000 s⁻¹ | discotic nematic graphene oxide |
Thickness | 20–1000 nm | — |
Thickness | 10–40 nm | — |
Thickness | 0.000001 cm | — |
Thickness | 500–4000 cm | — |
Thickness | 1–1150 cm | — |
Duration | ≤ 5 seconds | — |
Pressure | ≤ 2 bar | — |
Pressure | 0.0005–0.05 Pa | — |
Pressure | 0.001–0.04 Pa | — |
Pressure | 0.0016–0.03 Pa | — |
Pressure | 10–15 bar | — |
Duration | ≤ 1 hour | — |
Pressure | ≥ 50 Pa | — |
Pressure | ≥ 65 Pa | — |
Pressure | ≥ 80 Pa | — |
Pressure | ≥ 60 Pa | — |
Pressure | ≥ 70 Pa | — |
Pressure | ≥ 140 Pa | — |
Pressure | ≥ 160 Pa | — |
Pressure | ≥ 250 Pa | — |
Pressure | ≥ 300 Pa | — |
hydrogel beads
discotic nematic graphene oxide
porous substrate
reduced graphene oxide
superabsorbent polymer (sodium polyacrylate)
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
discotic nematic graphene oxide |
pore size of porous substrate support | 20–1000 nm | porous substrate |
shear rate during film coating | 1000-10000 s⁻¹ | discotic nematic graphene oxide |
Thickness | 20–1000 nm | — |
Thickness | 10–40 nm | — |
Thickness | 0.000001 cm | — |
Thickness | 500–4000 cm | — |
Thickness | 1–1150 cm | — |
Duration | ≤ 5 seconds | — |
Pressure | ≤ 2 bar | — |
Pressure | 0.0005–0.05 Pa | — |
Pressure | 0.001–0.04 Pa | — |
Pressure | 0.0016–0.03 Pa | — |
Pressure | 10–15 bar | — |
Duration | ≤ 1 hour | — |
Pressure | ≥ 50 Pa | — |
Pressure | ≥ 65 Pa | — |
Pressure | ≥ 80 Pa | — |
Pressure | ≥ 60 Pa | — |
Pressure | ≥ 70 Pa | — |
Pressure | ≥ 140 Pa | — |
Pressure | ≥ 160 Pa | — |
Pressure | ≥ 250 Pa | — |
Pressure | ≥ 300 Pa | — |
hydrogel beads
discotic nematic graphene oxide
porous substrate
reduced graphene oxide
superabsorbent polymer (sodium polyacrylate)
Figure 4: Graph showing zero-shear viscosity of the dispersions increases with increasing GO concentration and the inset shows large changes in the viscosity from 5 mg/m l coinciding with the onset of the isotropic to nematic phase transition.
Figure 5: Graph showing rheology data for three different concentrations showing shear-thinning behaviour. Solid curves are the fit of the experimental data with a power 20 law model.
Figure 9: Scanning electron microscopy characterization. SEM images of the top surface of our GO membranes cast by progressively increasing concentration: (a) 0.1 mg/m l, (b) 2.5 mg/m l, (c) 5 mg/m l, (d) 10 mg/m l, (e) 15 mg/m l, (f) 20 mg/m l, (g) 40 mg/m l, (h) 60 mg/m l. With increasing …
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 10: SEM images of an asymmetric membrane having a thickness of 10-40 nm thin membrane and on a porous nylon backing, made by 60mg/mL graphene oxide concentration. 10
Figure 13: SEM image showing continuity and conformity of SAM over a porous 15 Nylon substrate; scale bar is 1 pm.
Figure 16: XRD patterns of SAM and vacuum filtration membranes demonstrate 30 highly ordered lamellar structure for SAM.
Figure 17: XRD pattern of the SAM of GO and SAM after partially reduction in hydrazine vapour.
Figure 19: Graph showing height profile of SAM.
Figure 20: FTIR spectra of SAM of GO and SAM after partial reduction in hydrazine vapour. 5
Figure 21: Membrane testing equipment. A dead-end filtration cell (Sterlitech HP₄₇₅₀ with high pressure stirred cell) pressurized by nitrogen gas was used to examine the performance of the membranes.
Figure 22: Graph showing comparison of water permeability using SAM and vacuum filtration membrane. Error bars are from five measurements showing the 10 maximum and minimum values.
Figure 23: Graph showing comparison of retention of methyl red, an electroneutral probe molecule, using SAM and vacuum filtration membrane. Inset image is the structure of the electroneutral probe molecule. Error bars are from five measurements showing the maximum and minimum values. 15
Figure 25: Graph of pure water permeability and water permeability in the presence of probe molecules. Permeability declined during rejection tests with probe molecules. The results show that a maximum of 10% decline is observed, it is larger for 20 small molecules (methyl viologen-10% reduction), …
Figure 27: Graph showing retention performance of a 150 ± 15 nm thick shear- aligned membrane under 0.5 bar nitrogen pressure, as a function of hydrated radius, for probe molecules with different charges and sizes. (MV is methyl viologen, MR is methyl red, MnB is methylene blue, MO is methyl orange, …
Figure 28: Graph showing retention details of the membrane for the probe 5 molecules. Error bars are from five measurements showing the maximum and minimum values.
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 29: Graph showing water flux versus applied pressure for three different membranes: SAM (red) with a thickness of 150 ± 15 nm, vacuum filtration (blue) with a thickness of 170 ± 20 nm, and NF270, a commercial nanofiltration membrane (green). 10 Error bars are from five measurements showing the …
Figure 31: Graph showing salt retention by the 150 ± 15 nm thick SAM under 0.5 bar nitrogen pressure, for four different salt solutions. Error bars are from five 15 measurements showing the maximum and minimum values.
discotic nematic graphene oxide |
pore size of porous substrate support | 20–1000 nm | porous substrate |
shear rate during film coating | 1000-10000 s⁻¹ | discotic nematic graphene oxide |
Thickness | 20–1000 nm | — |
Thickness | 10–40 nm | — |
Thickness | 0.000001 cm | — |
Thickness | 500–4000 cm | — |
Thickness | 1–1150 cm | — |
Duration | ≤ 5 seconds | — |
Pressure | ≤ 2 bar | — |
Pressure | 0.0005–0.05 Pa | — |
Pressure | 0.001–0.04 Pa | — |
Pressure | 0.0016–0.03 Pa | — |
Pressure | 10–15 bar | — |
Duration | ≤ 1 hour | — |
Pressure | ≥ 50 Pa | — |
Pressure | ≥ 65 Pa | — |
Pressure | ≥ 80 Pa | — |
Pressure | ≥ 60 Pa | — |
Pressure | ≥ 70 Pa | — |
Pressure | ≥ 140 Pa | — |
Pressure | ≥ 160 Pa | — |
Pressure | ≥ 250 Pa | — |
Pressure | ≥ 300 Pa | — |