# US 12,215,027 B2 · Nanocarbon separation method and nanocarbon separation apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,215,027 B2 - Document ID: US12215027B2 - Status: Granted - Kind: B2 - Application number: 16/647,142 - Filed: 2017-09-29 - Published: 2020-09-03 - Granted: 2025-02-04 - Earliest claimed: 2017-09-29 - Assignees: NEC Corporation - Applicants: NEC Corporation - Inventors: Fumiyuki Nihey; Hideaki Numata - Web page: https://patentgrep.com/patent/US12215027B2 ## CPC - C01B 32/172: Sorting - B01D 57/02: by electrophoresis (treatment of water, waste water, sewage or sludge by electrophoresis C02F1/469; electrophoretic production of compounds or non-metals C25B7/00; investigating or analysing materials by using electrophoresis G01N27/26) - C01B 32/159: single-walled - C01B 2202/02: Single-walled nanotubes - C01B 2202/22: Electronic properties - Y10T 428/30: Self-sustaining carbon mass or layer with impregnant or other layer - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - 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) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A nanocarbon separation method includes: preparing a nanocarbon dispersion liquid in which nanocarbons and a non-ionic surfactant are dispersed in a solvent; injecting the nanocarbon dispersion liquid into a separation tank; applying a direct current voltage to a first electrode provided at an upper part of the interior of the separation tank and a second electrode provided at a lower part of the interior of the separation tank and generating a pH gradient in the nanocarbon dispersion liquid inside the separation tank, and separating metallic nanocarbons and semiconductor nanocarbons included in the nanocarbon dispersion liquid. ## Claims ### Claim 1 A nanocarbon separation method, comprising: preparing a nanocarbon dispersion liquid in which a nanocarbon and a non-ionic surfactant are dispersed in a solvent; injecting the nanocarbon dispersion liquid into a separation tank; applying a direct current voltage to a first electrode provided at an upper part of the interior of the separation tank and a second electrode provided at a lower part of the interior of the separation tank and generating a pH gradient in the nanocarbon dispersion liquid inside the separation tank; and separating metallic nanocarbons and semiconductor nanocarbons included in the nanocarbon dispersion liquid, wherein an amount of the non-ionic surfactant in the nanocarbon dispersion liquid in the separation tank is 1 wt % or more and 5 wt % or less. ### Claim 2 (depends on 1) The nanocarbon separation method according to claim 1, wherein the non-ionic surfactant is a polyoxyethylene alkyl ether represented by the following expression: CnH2n(OCH2CH2)mOH where, n=12 to 18 and m=20 to 100. ### Claim 3 (depends on 1) The nanocarbon separation method according to claim 1, wherein, when the direct current voltage is applied, an electric field between the first electrode and the second electrode is 0.5 V/cm or higher and 15 V/cm or lower. ### Claim 4 (depends on 1) The nanocarbon separation method according to claim 1, wherein the separation tank has a vertical type structure. ### Claim 5 (depends on 1) The nanocarbon separation method according to claim 1, wherein the solvent is water or heavy water. ### Claim 6 (depends on 1) The nanocarbon separation method according to claim 1, wherein, in the injecting the nanocarbon dispersion liquid into the separation tank, a solvent or a solution including the non-ionic surfactant, the solvent or the solution having a specific gravity smaller than that of the nanocarbon dispersion liquid is injected into a region which comes in contact with the first electrode and a solution having a specific gravity greater than that of the nanocarbon dispersion liquid and including the non-ionic surfactant is injected into a region which comes in contact with the second electrode. ### Claim 7 (depends on 1) The nanocarbon separation method according to claim 1, wherein the nanocarbons are single-walled carbon nanotubes. ### Claim 8 (depends on 1) The nanocarbon separation method according to claim 1, wherein the first electrode is a negative electrode, the second electrode is a positive electrode, and a direction of an electric field generated when the direct current voltage is applied to the first electrode and the second electrode is upward in a height direction of the separation tank. ### Claim 9 A nanocarbon separation apparatus used for separation of metallic nanocarbons and semiconductor nanocarbons included in a nanocarbon dispersion liquid in which nanocarbons and a non-ionic surfactant are dispersed in a solvent, the nanocarbon separation apparatus comprising: a separation tank which is configured to accommodate the nanocarbon dispersion liquid; and electrode members disposed inside the separation tank, wherein the separation tank has a lower end having an injection/recovery port communicating with an outer bottom surface of the separation tank, the electrode member includes a cylindrical member, a columnar member inserted into the cylindrical member, a first electrode provided on an outer circumferential surface of an upper end portion of the cylindrical member and a second electrode provided on a lower end portion of the columnar member, the columnar member is capable of moving in a height direction of the separation tank in a state being inserted into the cylindrical member, a lower end of the columnar member includes a fitting member configured to inscribe in a lower end portion of the cylindrical member when the columnar member moves upward in the height direction of the separation tank, and wherein at least a part of the second electrode is arranged inside the cylindrical member. ### Claim 10 (depends on 1) The nanocarbon separation method according to claim 1, wherein the amount of the non-ionic surfactant in the nanocarbon dispersion liquid in the separation tank is 1 wt % or more and 2 wt % or less. ### Claim 11 A nanocarbon separation method, comprising: preparing a separation tank and an electrode member provided in the separation tank wherein the electrode member comprises a cylindrical member, a columnar member inserted into the cylindrical member, a first electrode provided on an outer circumferential surface of an upper part of the cylindrical member, a second electrode provided at a lower part of the columnar member, and wherein at least a part of the second electrode is arranged inside the cylindrical member; preparing a nanocarbon dispersion liquid in which a nanocarbon and a non-ionic surfactant are dispersed in a solvent; injecting the nanocarbon dispersion liquid into the separation tank; applying a direct current voltage to the first electrode and the second electrode; separating metallic nanocarbons and semiconductor nanocarbons included in the nanocarbon dispersion liquid. ### Claim 12 (depends on 11) The nanocarbon separation method according to claim 11, wherein the second electrode and the cylindrical member are provided such that air bubbles generated by electrolysis at the second electrode move upwad inside the cylindrical member.