Patents by Inventor Han Kwon Chang

Han Kwon Chang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11362326
    Abstract: An embodiment of the present invention provides a method for preparing a silicon-carbon-graphene composite, comprising the steps of: (step 1) adding a carbon precursor solution to silicon and performing wet grinding so as to prepare a suspension: (step 2) forming a silicon-carbon composite by spray drying the suspension; and (step 3) spray drying and heat treating a solution comprising the silicon-carbon composite and graphene oxide.
    Type: Grant
    Filed: May 23, 2017
    Date of Patent: June 14, 2022
    Assignee: Korea Institute of Geoscience and Mineral Resources
    Inventors: Hee-Dong Jang, Han-Kwon Chang, Dae-Sup Kil, Ji-Hyuk Choi, Sun-Kyung Kim
  • Publication number: 20210242450
    Abstract: The present disclosure provides a method for manufacturing a silicon-carbon-graphene composite comprising, preparing a suspension in which silicon, carbon source and graphene oxide are dispersed, subjecting the suspension to an aerosol process to form a silicon-carbon source-graphene oxide composite and heat-treating the silicon-carbon source-graphene oxide composite to form a silicon-carbon-graphene composite, and prevents direct contact of the electrolyte, so it can exhibit excellent cycling performance and stability.
    Type: Application
    Filed: September 28, 2020
    Publication date: August 5, 2021
    Applicant: Korea Institute Of Geoscience And Mineral Resources
    Inventors: Hee Dong JANG, Han Kwon CHANG, Sun Kyung KIM
  • Patent number: 10822237
    Abstract: A method for preparing graphene balls, the method including, a) preparing a dispersion which includes, a graphene oxide, a reducing agent ranging from a monosaccharide to a polysaccharide, ammonia water and a dispersion medium; and b) spraying and drying the dispersion. According to the preparation method of the present disclosure, it is possible to prepare uniformly sized and spherical graphene balls. Such graphene can be applied to various fields due to excellent physical and chemical characteristics.
    Type: Grant
    Filed: March 14, 2017
    Date of Patent: November 3, 2020
    Assignee: Korea Institute Of Geoscience And Mineral Resources
    Inventors: Hee-Dong Jang, Han-Kwon Chang, Ji-Hyuk Choi
  • Publication number: 20190355985
    Abstract: An embodiment of the present invention provides a method for preparing a silicon-carbon-graphene composite, comprising the steps of: (step 1) adding a carbon precursor solution to silicon and performing wet grinding so as to prepare a suspension: (step 2) forming a silicon-carbon composite by spray drying the suspension; and (step 3) spray drying and heat treating a solution comprising the silicon-carbon composite and graphene oxide.
    Type: Application
    Filed: May 23, 2017
    Publication date: November 21, 2019
    Applicant: Korea Institute of Geoscience And Mineral Resources
    Inventors: Hee-Dong JANG, Han-Kwon CHANG, Dae-Sup Kil, Ji-Hyuk Choi, Sun-Kyung Kim
  • Publication number: 20190112194
    Abstract: A method for preparing graphene balls, the method including, a) preparing a dispersion which includes, a graphene oxide, a reducing agent ranging from a monosaccharide to a polysaccharide, ammonia water and a dispersion medium; and b) spraying and drying the dispersion. According to the preparation method of the present disclosure, it is possible to prepare uniformly sized and spherical graphene balls. Such graphene can be applied to various fields due to excellent physical and chemical characteristics.
    Type: Application
    Filed: March 14, 2017
    Publication date: April 18, 2019
    Applicant: Korea Institute Of Geoscience And Mineral Resources
    Inventors: Hee-Dong JANG, Han-Kwon CHANG, Ji-Hyuk CHOI
  • Patent number: 9296617
    Abstract: Disclosed is a method for selectively separating and recovering silicon from waste silicon sludge generated during a semiconductor manufacturing process. With the method for separating and recovering silicon from the silicon sludge, oil components, iron, silicon carbide that are included in the silicon sludge may be removed and silicon may be selectively separated and recovered. In addition, silicon may be efficiently recovered without injection of an additive for precipitating a specific component or without a separate device such as a magnetic separator, or the like, for removing iron.
    Type: Grant
    Filed: October 17, 2012
    Date of Patent: March 29, 2016
    Assignee: Korea Institute of Geoscience and Mineral Resources
    Inventors: Hee Dong Jang, Han Kwon Chang, Dae Sup Kil
  • Patent number: 9272917
    Abstract: Disclosed is a method of preparing mesoporous silica particles. The method includes (a) preparing an aqueous silicic acid, (b) spraying the aqueous silicic acid in a droplet state by activating the aqueous silicic acid, and (c) pyrolyzing the sprayed droplet through a reactor, which is previously heated, by allowing the sprayed droplet to pass through the reactor together with a carrier gas. The aqueous silicic acid includes 0.4 M to 0.8 M of silicic acid.
    Type: Grant
    Filed: November 14, 2012
    Date of Patent: March 1, 2016
    Assignee: KOREA INSTITUTE OF GEOSCIENCE AND MINERAL RESOURCES
    Inventors: Han Kwon Chang, Hee Dong Jang
  • Patent number: 8986906
    Abstract: The present invention provides a method for preparing nanoporous Pt/TiO2 composite particles, nanoporous Pt/TiO2 composite particles prepared by the above preparation method, and a fuel cell comprising the nanoporous Pt/TiO2 composite particles. The nanoporous Pt/TiO2 composite particles according to the present invention have a catalytic effect similar to that of commercially available Pt/carbon black and, thus, can be applied to a fuel cell.
    Type: Grant
    Filed: July 14, 2011
    Date of Patent: March 24, 2015
    Assignee: Korea Institute of Geoscience and Mineral Resources
    Inventors: Hee Dong Jang, Han Kwon Chang, Kuk Cho
  • Patent number: 8967492
    Abstract: A droplet generation system includes a first nozzle configuration structured to receive a liquid and a gas under pressure in a controllable feed ratio, and to merge the liquid and gas to form an intermediate stream that is a mixture of the gas and of a dispersed phase of the liquid. A second nozzle configuration is connected to receive the intermediate stream from the first nozzle configuration and has a valve mechanism with one or more controllable operating parameters to emit a stream of droplets of the liquid. The mean size of the droplets is dependent on the controllable feed ratio of the liquid and gas and the flow rate of the stream of droplets is dependent on the controllable operating parameter(s) of the valve mechanism. A corresponding method is disclosed, as is the application of the system and method to the production of nanoparticles in a thermochemical reactor.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: March 3, 2015
    Assignee: Commonwealth Scientific and Industrial Research Organisation
    Inventors: Jonian Nikolov, Kok Seng Lim, Han Kwon Chang, Hee Dong Jang
  • Publication number: 20140339078
    Abstract: Provided is a glucose sensor. The glucose sensor according to the present invention includes noble metal-graphene composites, and has high sensitivity and significantly excellent current flow as compared to titanium dioxide-graphene composites. In addition, the noble metal-graphene composite manufactured by aerosol spray pyrolysis serves as an improved glucose sensor having desirable sensitivity, stability, reproducibility, and selectivity.
    Type: Application
    Filed: September 17, 2013
    Publication date: November 20, 2014
    Applicant: KOREA INSTITUTE OF GEOSCIENCE AND MINERAL RESOURCES
    Inventors: Hee Dong JANG, Han Kwon CHANG, Sun Kyung KIM, Ki Min ROH
  • Patent number: 8883254
    Abstract: Disclosed is a method of synthesizing hollow silica having the size of micrometers from sodium silicate. The method includes fabricating a polystyrene organic template from polystyrene latex, (B) cleaning the polystyrene organic template, (C) exchanging media by using a water-base medium, introducing the cleaned polystyrene organic template and sodium silicate, and preparing a silica-coated organic template by performing an acidic hydrolysis reaction, and (D) cleaning the silica-coated organic template included in the water-base medium by using water. The size of the organic template is adjusted by controlling an amount of introduced AIBN included when the organic template is fabricated. The cleaning of the organic template is preferably performed by using water (H2O). The method further includes (B) removing the organic template by using THF and (F) cleaning the hollow silica having no organic template.
    Type: Grant
    Filed: November 12, 2013
    Date of Patent: November 11, 2014
    Assignee: Korea Institute of Geoscience and Mineral Resources
    Inventors: Jiwoong Kim, Hee Dong Jang, Han Kwon Chang
  • Publication number: 20140141163
    Abstract: Disclosed is a method of synthesizing hollow silica having the size of micrometers from sodium silicate. The method includes fabricating a polystyrene organic template from polystyrene latex, (B) cleaning the polystyrene organic template, (C) exchanging media by using a water-base medium, introducing the cleaned polystyrene organic template and sodium silicate, and preparing a silica-coated organic template by performing an acidic hydrolysis reaction, and (D) cleaning the silica-coated organic template included in the water-base medium by using water. The size of the organic template is adjusted by controlling an amount of introduced AIBN included when the organic template is fabricated. The cleaning of the organic template is preferably performed by using water (H2O). The method further includes (B) removing the organic template by using THF and (F) cleaning the hollow silica having no organic template.
    Type: Application
    Filed: November 12, 2013
    Publication date: May 22, 2014
    Applicant: Korea Institute of Geoscience and Mineral Resources
    Inventors: Jiwoong Kim, Hee Dong Jang, Han Kwon Chang
  • Publication number: 20140017154
    Abstract: Disclosed is a method of preparing mesoporous silica particles. The method includes (a) preparing an aqueous silicic acid, (b) spraying the aqueous silicic acid in a droplet state by activating the aqueous silicic acid, and (c) pyrolyzing the sprayed droplet through a reactor, which is previously heated, by allowing the sprayed droplet to pass through the reactor together with a carrier gas. The aqueous silicic acid includes 0.4 M to 0.8 M of silicic acid.
    Type: Application
    Filed: November 14, 2012
    Publication date: January 16, 2014
    Applicant: KOREA INSTITUTE OF GEOSCIENCE AND MINERAL RESOURCES
    Inventors: Han Kwon Chang, Hee Dong Jang
  • Publication number: 20130277201
    Abstract: Disclosed is a method for selectively separating and recovering silicon from waste silicon sludge generated during a semiconductor manufacturing process. With the method for separating and recovering silicon from the silicon sludge, oil components, iron, silicon carbide that are included in the silicon sludge may be removed and silicon may be selectively separated and recovered. In addition, silicon may be efficiently recovered without injection of an additive for precipitating a specific component or without a separate device such as a magnetic separator, or the like, for removing iron.
    Type: Application
    Filed: October 17, 2012
    Publication date: October 24, 2013
    Inventors: Hee Dong Jang, Han Kwon Chang, Dae Sup Kil
  • Patent number: 8562815
    Abstract: Provided is a glucose sensor including a titanium dioxide-graphene composite having a porous structure. More particularly, the glucose sensor includes a working electrode having the titanium dioxide-graphene composite having the porous structure and an enzyme to provide features that allow a current flow to be excellent, a current to be sensitively changed depending on a change in electric potential, sensitivity to be high, and a low voltage characteristic to be excellent.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: October 22, 2013
    Assignee: Korea Institute of Geoscience and Mineral Resources
    Inventors: Hee-Dong Jang, Han-Kwon Chang, Sun-Kyung Kim
  • Publication number: 20130101500
    Abstract: A droplet generation system includes a first nozzle configuration structured to receive a liquid and a gas under pressure in a controllable feed ratio, and to merge the liquid and gas to form an intermediate stream that is a mixture of the gas and of a dispersed phase of the liquid. A second nozzle configuration is connected to receive the intermediate stream from the first nozzle configuration and has a valve mechanism with one or more controllable operating parameters to emit a stream of droplets of the liquid. The mean size of the droplets is dependent on the controllable feed ratio of the liquid and gas and the flow rate of the stream of droplets is dependent on the controllable operating parameter(s) of the valve mechanism. A corresponding method is disclosed, as is the application of the system and method to the production of nanoparticles in a thermochemical reactor.
    Type: Application
    Filed: June 30, 2011
    Publication date: April 25, 2013
    Applicants: KOREA INSTITUTE OF GEOSCIENCE AND MINERAL RESOURCES, COMMONWEALTH SCIENTIFIC AND INDUSTRIAL RESEARCH ORGANISATION
    Inventors: Jonian Nikolov, Kok Seng Lim, Han Kwon Chang, Hee Dong Jang
  • Publication number: 20130062201
    Abstract: Provided is a glucose sensor including a titanium dioxide-graphene composite having a porous structure. More particularly, the glucose sensor includes a working electrode having the titanium dioxide-graphene composite having the porous structure and an enzyme to provide features that allow a current flow to be excellent, a current to be sensitively changed depending on a change in electric potential, sensitivity to be high, and a low voltage characteristic to be excellent.
    Type: Application
    Filed: October 27, 2011
    Publication date: March 14, 2013
    Applicant: Korea Institute of Geoscience and Mineral Resources
    Inventors: Hee-Dong Jang, Han-Kwon Chang, Sun-Kyung Kim
  • Publication number: 20120219882
    Abstract: The present invention provides a method for preparing nanoporous Pt/TiO2 composite particles, nanoporous Pt/TiO2 composite particles prepared by the above preparation method, and a fuel cell comprising the nanoporous Pt/TiO2 composite particles. The nanoporous Pt/TiO2 composite particles according to the present invention have a catalytic effect similar to that of commercially available Pt/carbon black and, thus, can be applied to a fuel cell.
    Type: Application
    Filed: July 14, 2011
    Publication date: August 30, 2012
    Inventors: Hee Dong Jang, Han Kwon Chang, Kuk Cho
  • Patent number: 8187562
    Abstract: Disclosed is a method for producing a cerium dioxide nanopowder by flame spray pyrolysis. The method comprises dissolving a cerium compound in an organic solvent to prepare a precursor solution, atomizing the precursor solution into microdroplets using an ultrasonic atomizer, transferring the microdroplets together with an argon gas as a carrier gas to a central portion of a high-temperature diffusion flame burner, subjecting the microdroplets to pyrolysis and oxidation in the central portion of the diffusion flame burner to produce a cerium dioxide nanopowder, and collecting the cerium dioxide nanopowder using a collector. According to the method, a cerium dioxide nanopowder can be continuously produced on a large scale by flame spray pyrolysis. In addition, the particle size and uniformity of the cerium dioxide nanopowder can be controlled by appropriately selecting the kind of the solvent and the concentration of the raw material.
    Type: Grant
    Filed: November 24, 2010
    Date of Patent: May 29, 2012
    Assignee: Korea Institute of Geoscience and Mineral Resources (KIGAM)
    Inventors: Han Kwon Chang, Hee Dong Jang, Dae Sup Kil, Kuk Cho, Sung-Wook Cho
  • Publication number: 20120046159
    Abstract: Disclosed is a method for recovering cobalt and manganese from a spent cobalt-manganese-bromine (CMB) catalyst. The method includes (a) continuously leaching a spent CMB catalyst with sulfuric acid, (b) separating the leachate into a solution and a residue, (c) extracting the solution with a solvent, and (d) washing the extract with water. According to the method, high-purity cobalt and manganese can be recovered in high yield from a spent CMB catalyst while minimizing the amount of impurities. Further disclosed is a method for producing a CMB liquid catalyst from the extract containing cobalt and manganese obtained by the recovery method.
    Type: Application
    Filed: August 16, 2011
    Publication date: February 23, 2012
    Inventors: Shun Myung SHIN, Sung Ho Ju, Jin Gu Kang, Han Kwon Chang, Jeong Soo Sohn