Patents by Inventor Joan Jang

Joan Jang 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: 8524067
    Abstract: A method of producing nano-scaled graphene platelets with an average thickness smaller than 30 nm from a layered graphite material. The method comprises (a) forming a carboxylic acid-intercalated graphite compound by an electrochemical reaction; (b) exposing the intercalated graphite compound to a thermal shock to produce exfoliated graphite; and (c) subjecting the exfoliated graphite to a mechanical shearing treatment to produce the nano-scaled graphene platelets. Preferred carboxylic acids are formic acid and acetic acid. The exfoliation step in the instant invention does not involve the evolution of undesirable species, such as NOx and SOx, which are common by-products of exfoliating conventional sulfuric or nitric acid-intercalated graphite compounds. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: September 3, 2013
    Assignee: Nanotek Instruments, Inc.
    Inventors: Aruna Zhamu, Joan Jang, Bor Z. Jang
  • Publication number: 20090026086
    Abstract: A method of producing nano-scaled graphene platelets with an average thickness smaller than 30 nm from a layered graphite material. The method comprises (a) forming a carboxylic acid-intercalated graphite compound by an electrochemical reaction which uses a carboxylic acid as both an electrolyte and an intercalate source, the layered graphite material as an anode material, and a metal or graphite as a cathode material, and wherein a current is imposed upon the cathode and the anode at a current density for a duration of time sufficient for effecting the electrochemical reaction; (b) exposing the intercalated graphite compound to a thermal shock to produce exfoliated graphite; and (c) subjecting the exfoliated graphite to a mechanical shearing treatment to produce the nano-scaled graphene platelets. Preferred carboxylic acids are formic acid and acetic acid.
    Type: Application
    Filed: July 27, 2007
    Publication date: January 29, 2009
    Inventors: Aruna Zhamu, Joan Jang, Bor Z. Jang
  • Publication number: 20090022649
    Abstract: A method of producing ultra-thin, separated nano-scaled platelets having an average thickness no greater than 2 nm or comprising, on average, no more than 5 layers per platelet from a layered graphite material. The method comprises: (a) providing a supply of nano-scaled platelets with an average thickness of no more than 10 nm or having, on average, no more than 30 layers per platelet; and (b) intercalating the supply of nano-scaled platelets to produce intercalated nano platelets and exfoliating the intercalated nano platelets at a temperature and a pressure for a sufficient period of time to produce the ultra-thin nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers.
    Type: Application
    Filed: July 19, 2007
    Publication date: January 22, 2009
    Inventors: Aruna Zhamu, Jinjun Shi, Joan Jang, Bor Z. Jang