Patent
US 8,672,246Method for Purifying Graphene Powder
Jae Kap LEE
US
Copyright © 2026 Matter42. All rights reserved.
Patent
Atlas literature
Patent
US 8,672,246Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a schematic drawing to show a state in which the entirety of ball- milled graphene powder (1) swept to a magnet (3) along with magnetic impurities 25 …
FIG. 2 is a schematic drawing to show each step of a method for purifying graphene powder according to an embodiment of the present invention.
FIG. 3(c) is a photograph showing a state in which magnetic impurities (2) separated upon using magnet (3) in the purifying process of an 10 embodiment of the …
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 purifying graphene powder, the method including: (1) ball-milling a graphite material by usin g a stainless ball to form graphene powder to be a size of 100 nm or smaller; (2) dispersing the graphene powder in a solvent to form a suspension; and (3) separating magnetic impurities during stirring the suspension, by using a magnet, Wherein wherein the magnetic impurities were incorporated into the graphene powder during ball-milling from the balls and dispersed in the suspension, and wherein the dispersing in step (2), the stirring in step (3), or the dispersin g and the stirring in step (2) and step (3) is performed by using ultrasonication.
The method of claim 1, wherein the graphite material is in the form of a helix.
The method of claim 1, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 1, wherein step (3) is performed repeatedly on a remaining suspension from which magnetic impurities were separated, after performing the step (3) in claim 1.
canceled
canceled
A method for purifying graphene powder, the method including: (1) ba l l-milling a multiwalled tube-like graphite material having a helical form of a graphene ribbon to form graphene nano-powder by using a ball-milling apparatus with stainless balls with a diameter of 6 mm for two hours; (2) dispersing the graphene nano-powder in a solvent to form a suspension; (3) stirring the suspension, wherein magnetic impurities were incorporated into the graphene nano-powder during ball-milling from the balls and dispersed in the suspension; (4) placing a magnet in the suspension, wherein the magnetic impurities stick to the magnet.
The method of claim 7, wherein the graphite material is in the form of a helix.
The method of claim 7, wherein the ball-milling is performed to make Page 3 of 8 Application Serial No. 13/211,609 PATENT Reply to non-final office action of Docket: CU-9299 the graphene powder to be a size of 100 nm or smaller.
The method of claim 7, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 7, wherein the dispersing in step (2), the stirring in step (3), or the dispersing and the stirring in step (2) and step (3) is performed by using ultrasonication.
Embodiments described in the patent, grouped by the materials and process steps they use.
3 materials1 process step
1 g of a multi-walled tube-like graphite material (average outer diameter ≤20 nm, average inner diameter ≤5 nm, length 2–3 µm) having a helical form of a graphene ribbon (width ≤5 nm, thickness ≤10 nm) was ball-milled using a spex ball-milling apparatus with a stainless ball of 6 mm diameter for two hours to produce graphene nano-powder. After ball-milling, sample weight was 1.2 g. X-ray analysis confirmed iron-based impurities (~20 wt%) incorporated during ball-milling. TEM observation confirmed nano-powder/nano-ribbon morphology (thickness ≤0.4 nm, width ≤5 nm, length ≤20 nm) coexisting with iron-based impurities of tens of nm or smaller. Conventional dry magnetic separation was found ineffective.
3 materials1 process step
0.5 g of the ball-milled graphene sample from Example 1 was placed in a 200-cc beaker and ultrasonicated for 1 minute in alcohol to create a suspension. A magnet (diameter 10 mm, length 100 mm, (BH)Max 4.0 MGOe) was placed in the beaker and the suspension was additionally ultrasonicated for 5 minutes. Upon removal of the magnet, ~0.1 g of iron-based impurities adhered to it. X-ray analysis of the purified graphene sample showed no detectable impurity. The purified graphene remained suspended in alcohol for months.
Measurements and analyses referenced in the patent, with their drawing references.
X-ray analysis of ball-milled sample confirmed presence of iron-based impurities (~20 wt%) after ball-milling (Example 1). After purification (Example 2), X-ray analysis of purified graphene showed no detectable impurity; impurities removed confirmed to be iron-based metal matching ball composition.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene nano-powder particle size after ball-milling | ≤ 100 nm | graphene nano-powder (nano-ribbon) |
iron-based impurity content after ball-milling (Example 1) | 20 wt% |
Patent
Atlas literature
Patent
US 8,672,246Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a schematic drawing to show a state in which the entirety of ball- milled graphene powder (1) swept to a magnet (3) along with magnetic impurities 25 …
FIG. 2 is a schematic drawing to show each step of a method for purifying graphene powder according to an embodiment of the present invention.
FIG. 3(c) is a photograph showing a state in which magnetic impurities (2) separated upon using magnet (3) in the purifying process of an 10 embodiment of the …
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 purifying graphene powder, the method including: (1) ball-milling a graphite material by usin g a stainless ball to form graphene powder to be a size of 100 nm or smaller; (2) dispersing the graphene powder in a solvent to form a suspension; and (3) separating magnetic impurities during stirring the suspension, by using a magnet, Wherein wherein the magnetic impurities were incorporated into the graphene powder during ball-milling from the balls and dispersed in the suspension, and wherein the dispersing in step (2), the stirring in step (3), or the dispersin g and the stirring in step (2) and step (3) is performed by using ultrasonication.
The method of claim 1, wherein the graphite material is in the form of a helix.
The method of claim 1, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 1, wherein step (3) is performed repeatedly on a remaining suspension from which magnetic impurities were separated, after performing the step (3) in claim 1.
canceled
canceled
A method for purifying graphene powder, the method including: (1) ba l l-milling a multiwalled tube-like graphite material having a helical form of a graphene ribbon to form graphene nano-powder by using a ball-milling apparatus with stainless balls with a diameter of 6 mm for two hours; (2) dispersing the graphene nano-powder in a solvent to form a suspension; (3) stirring the suspension, wherein magnetic impurities were incorporated into the graphene nano-powder during ball-milling from the balls and dispersed in the suspension; (4) placing a magnet in the suspension, wherein the magnetic impurities stick to the magnet.
The method of claim 7, wherein the graphite material is in the form of a helix.
The method of claim 7, wherein the ball-milling is performed to make Page 3 of 8 Application Serial No. 13/211,609 PATENT Reply to non-final office action of Docket: CU-9299 the graphene powder to be a size of 100 nm or smaller.
The method of claim 7, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 7, wherein the dispersing in step (2), the stirring in step (3), or the dispersing and the stirring in step (2) and step (3) is performed by using ultrasonication.
Embodiments described in the patent, grouped by the materials and process steps they use.
3 materials1 process step
1 g of a multi-walled tube-like graphite material (average outer diameter ≤20 nm, average inner diameter ≤5 nm, length 2–3 µm) having a helical form of a graphene ribbon (width ≤5 nm, thickness ≤10 nm) was ball-milled using a spex ball-milling apparatus with a stainless ball of 6 mm diameter for two hours to produce graphene nano-powder. After ball-milling, sample weight was 1.2 g. X-ray analysis confirmed iron-based impurities (~20 wt%) incorporated during ball-milling. TEM observation confirmed nano-powder/nano-ribbon morphology (thickness ≤0.4 nm, width ≤5 nm, length ≤20 nm) coexisting with iron-based impurities of tens of nm or smaller. Conventional dry magnetic separation was found ineffective.
3 materials1 process step
0.5 g of the ball-milled graphene sample from Example 1 was placed in a 200-cc beaker and ultrasonicated for 1 minute in alcohol to create a suspension. A magnet (diameter 10 mm, length 100 mm, (BH)Max 4.0 MGOe) was placed in the beaker and the suspension was additionally ultrasonicated for 5 minutes. Upon removal of the magnet, ~0.1 g of iron-based impurities adhered to it. X-ray analysis of the purified graphene sample showed no detectable impurity. The purified graphene remained suspended in alcohol for months.
Measurements and analyses referenced in the patent, with their drawing references.
X-ray analysis of ball-milled sample confirmed presence of iron-based impurities (~20 wt%) after ball-milling (Example 1). After purification (Example 2), X-ray analysis of purified graphene showed no detectable impurity; impurities removed confirmed to be iron-based metal matching ball composition.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene nano-powder particle size after ball-milling | ≤ 100 nm | graphene nano-powder (nano-ribbon) |
iron-based impurity content after ball-milling (Example 1) | 20 wt% |
Patent
Atlas literature
Patent
US 8,672,246Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a schematic drawing to show a state in which the entirety of ball- milled graphene powder (1) swept to a magnet (3) along with magnetic impurities 25 …
FIG. 2 is a schematic drawing to show each step of a method for purifying graphene powder according to an embodiment of the present invention.
FIG. 3(c) is a photograph showing a state in which magnetic impurities (2) separated upon using magnet (3) in the purifying process of an 10 embodiment of the …
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 purifying graphene powder, the method including: (1) ball-milling a graphite material by usin g a stainless ball to form graphene powder to be a size of 100 nm or smaller; (2) dispersing the graphene powder in a solvent to form a suspension; and (3) separating magnetic impurities during stirring the suspension, by using a magnet, Wherein wherein the magnetic impurities were incorporated into the graphene powder during ball-milling from the balls and dispersed in the suspension, and wherein the dispersing in step (2), the stirring in step (3), or the dispersin g and the stirring in step (2) and step (3) is performed by using ultrasonication.
The method of claim 1, wherein the graphite material is in the form of a helix.
The method of claim 1, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 1, wherein step (3) is performed repeatedly on a remaining suspension from which magnetic impurities were separated, after performing the step (3) in claim 1.
canceled
canceled
A method for purifying graphene powder, the method including: (1) ba l l-milling a multiwalled tube-like graphite material having a helical form of a graphene ribbon to form graphene nano-powder by using a ball-milling apparatus with stainless balls with a diameter of 6 mm for two hours; (2) dispersing the graphene nano-powder in a solvent to form a suspension; (3) stirring the suspension, wherein magnetic impurities were incorporated into the graphene nano-powder during ball-milling from the balls and dispersed in the suspension; (4) placing a magnet in the suspension, wherein the magnetic impurities stick to the magnet.
The method of claim 7, wherein the graphite material is in the form of a helix.
The method of claim 7, wherein the ball-milling is performed to make Page 3 of 8 Application Serial No. 13/211,609 PATENT Reply to non-final office action of Docket: CU-9299 the graphene powder to be a size of 100 nm or smaller.
The method of claim 7, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 7, wherein the dispersing in step (2), the stirring in step (3), or the dispersing and the stirring in step (2) and step (3) is performed by using ultrasonication.
Embodiments described in the patent, grouped by the materials and process steps they use.
3 materials1 process step
1 g of a multi-walled tube-like graphite material (average outer diameter ≤20 nm, average inner diameter ≤5 nm, length 2–3 µm) having a helical form of a graphene ribbon (width ≤5 nm, thickness ≤10 nm) was ball-milled using a spex ball-milling apparatus with a stainless ball of 6 mm diameter for two hours to produce graphene nano-powder. After ball-milling, sample weight was 1.2 g. X-ray analysis confirmed iron-based impurities (~20 wt%) incorporated during ball-milling. TEM observation confirmed nano-powder/nano-ribbon morphology (thickness ≤0.4 nm, width ≤5 nm, length ≤20 nm) coexisting with iron-based impurities of tens of nm or smaller. Conventional dry magnetic separation was found ineffective.
3 materials1 process step
0.5 g of the ball-milled graphene sample from Example 1 was placed in a 200-cc beaker and ultrasonicated for 1 minute in alcohol to create a suspension. A magnet (diameter 10 mm, length 100 mm, (BH)Max 4.0 MGOe) was placed in the beaker and the suspension was additionally ultrasonicated for 5 minutes. Upon removal of the magnet, ~0.1 g of iron-based impurities adhered to it. X-ray analysis of the purified graphene sample showed no detectable impurity. The purified graphene remained suspended in alcohol for months.
Measurements and analyses referenced in the patent, with their drawing references.
X-ray analysis of ball-milled sample confirmed presence of iron-based impurities (~20 wt%) after ball-milling (Example 1). After purification (Example 2), X-ray analysis of purified graphene showed no detectable impurity; impurities removed confirmed to be iron-based metal matching ball composition.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene nano-powder particle size after ball-milling | ≤ 100 nm | graphene nano-powder (nano-ribbon) |
iron-based impurity content after ball-milling (Example 1) | 20 wt% |
Patent
Atlas literature
Patent
US 8,672,246Patent drawings and their descriptions. Click a drawing to enlarge it.
FIG. 1 is a schematic drawing to show a state in which the entirety of ball- milled graphene powder (1) swept to a magnet (3) along with magnetic impurities 25 …
FIG. 2 is a schematic drawing to show each step of a method for purifying graphene powder according to an embodiment of the present invention.
FIG. 3(c) is a photograph showing a state in which magnetic impurities (2) separated upon using magnet (3) in the purifying process of an 10 embodiment of the …
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 purifying graphene powder, the method including: (1) ball-milling a graphite material by usin g a stainless ball to form graphene powder to be a size of 100 nm or smaller; (2) dispersing the graphene powder in a solvent to form a suspension; and (3) separating magnetic impurities during stirring the suspension, by using a magnet, Wherein wherein the magnetic impurities were incorporated into the graphene powder during ball-milling from the balls and dispersed in the suspension, and wherein the dispersing in step (2), the stirring in step (3), or the dispersin g and the stirring in step (2) and step (3) is performed by using ultrasonication.
The method of claim 1, wherein the graphite material is in the form of a helix.
The method of claim 1, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 1, wherein step (3) is performed repeatedly on a remaining suspension from which magnetic impurities were separated, after performing the step (3) in claim 1.
canceled
canceled
A method for purifying graphene powder, the method including: (1) ba l l-milling a multiwalled tube-like graphite material having a helical form of a graphene ribbon to form graphene nano-powder by using a ball-milling apparatus with stainless balls with a diameter of 6 mm for two hours; (2) dispersing the graphene nano-powder in a solvent to form a suspension; (3) stirring the suspension, wherein magnetic impurities were incorporated into the graphene nano-powder during ball-milling from the balls and dispersed in the suspension; (4) placing a magnet in the suspension, wherein the magnetic impurities stick to the magnet.
The method of claim 7, wherein the graphite material is in the form of a helix.
The method of claim 7, wherein the ball-milling is performed to make Page 3 of 8 Application Serial No. 13/211,609 PATENT Reply to non-final office action of Docket: CU-9299 the graphene powder to be a size of 100 nm or smaller.
The method of claim 7, wherein the solvent is alcohol, acetone, DMF(dimethylformamide), or toluene.
The method of claim 7, wherein the dispersing in step (2), the stirring in step (3), or the dispersing and the stirring in step (2) and step (3) is performed by using ultrasonication.
Embodiments described in the patent, grouped by the materials and process steps they use.
3 materials1 process step
1 g of a multi-walled tube-like graphite material (average outer diameter ≤20 nm, average inner diameter ≤5 nm, length 2–3 µm) having a helical form of a graphene ribbon (width ≤5 nm, thickness ≤10 nm) was ball-milled using a spex ball-milling apparatus with a stainless ball of 6 mm diameter for two hours to produce graphene nano-powder. After ball-milling, sample weight was 1.2 g. X-ray analysis confirmed iron-based impurities (~20 wt%) incorporated during ball-milling. TEM observation confirmed nano-powder/nano-ribbon morphology (thickness ≤0.4 nm, width ≤5 nm, length ≤20 nm) coexisting with iron-based impurities of tens of nm or smaller. Conventional dry magnetic separation was found ineffective.
3 materials1 process step
0.5 g of the ball-milled graphene sample from Example 1 was placed in a 200-cc beaker and ultrasonicated for 1 minute in alcohol to create a suspension. A magnet (diameter 10 mm, length 100 mm, (BH)Max 4.0 MGOe) was placed in the beaker and the suspension was additionally ultrasonicated for 5 minutes. Upon removal of the magnet, ~0.1 g of iron-based impurities adhered to it. X-ray analysis of the purified graphene sample showed no detectable impurity. The purified graphene remained suspended in alcohol for months.
Measurements and analyses referenced in the patent, with their drawing references.
X-ray analysis of ball-milled sample confirmed presence of iron-based impurities (~20 wt%) after ball-milling (Example 1). After purification (Example 2), X-ray analysis of purified graphene showed no detectable impurity; impurities removed confirmed to be iron-based metal matching ball composition.
Performance values and ranges asserted in the specification or claims.
| Property | Value | Material |
|---|---|---|
graphene nano-powder particle size after ball-milling | ≤ 100 nm | graphene nano-powder (nano-ribbon) |
iron-based impurity content after ball-milling (Example 1) | 20 wt% |
TEM observation confirmed graphene nano-powder/nano-ribbon morphology with thickness ≤0.4 nm, width ≤5 nm, and length ≤20 nm coexisting with iron-based impurities of tens of nm or smaller.
iron-based magnetic impurities |
graphene nano-ribbon thickness (TEM, Example 1) | ≤ 0.4 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon width (TEM, Example 1) | ≤ 5 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon length (TEM, Example 1) | ≤ 20 nm | graphene nano-powder (nano-ribbon) |
TEM observation confirmed graphene nano-powder/nano-ribbon morphology with thickness ≤0.4 nm, width ≤5 nm, and length ≤20 nm coexisting with iron-based impurities of tens of nm or smaller.
iron-based magnetic impurities |
graphene nano-ribbon thickness (TEM, Example 1) | ≤ 0.4 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon width (TEM, Example 1) | ≤ 5 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon length (TEM, Example 1) | ≤ 20 nm | graphene nano-powder (nano-ribbon) |
TEM observation confirmed graphene nano-powder/nano-ribbon morphology with thickness ≤0.4 nm, width ≤5 nm, and length ≤20 nm coexisting with iron-based impurities of tens of nm or smaller.
iron-based magnetic impurities |
graphene nano-ribbon thickness (TEM, Example 1) | ≤ 0.4 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon width (TEM, Example 1) | ≤ 5 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon length (TEM, Example 1) | ≤ 20 nm | graphene nano-powder (nano-ribbon) |
TEM observation confirmed graphene nano-powder/nano-ribbon morphology with thickness ≤0.4 nm, width ≤5 nm, and length ≤20 nm coexisting with iron-based impurities of tens of nm or smaller.
iron-based magnetic impurities |
graphene nano-ribbon thickness (TEM, Example 1) | ≤ 0.4 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon width (TEM, Example 1) | ≤ 5 nm | graphene nano-powder (nano-ribbon) |
graphene nano-ribbon length (TEM, Example 1) | ≤ 20 nm | graphene nano-powder (nano-ribbon) |