Patents by Inventor Nanwen Li

Nanwen Li 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).

  • Publication number: 20220363811
    Abstract: The present invention relates to the field of hydrogen energy, and more particularly to an anion-conducting polyelectrolyte comprising an amide group, a preparation method and application thereof. The method includes: polymerizing aromatic hydrocarbons and ketone comprising amide group by superacid catalysis, forming a membrane by a casting method, performing the membrane prepared under alkaline conditions to obtain the anion-conducting polyelectrolytes comprising amide group. The anion-conducting polyelectrolytes obtained have good solubility and excellent stability. It is a kind of high molecular polymer with excellent alkali stability with an amide structure on the backbone. After alkaline treatment, the polymer not only has high hydroxide conductivity, good mechanical properties, and thermal stability but also has excellent alkali stability and excellent performance of water electrolysis.
    Type: Application
    Filed: June 22, 2022
    Publication date: November 17, 2022
    Inventors: Nanwen Li, Xu Hu, Yingda Huang, Bin Hu
  • Patent number: 9718923
    Abstract: One method as described herein relates to making a high molecular weight, monoesterified polyimide polymer using a small amount of bulky diamine. These high molecular weight, monoesterified polyimide polymers are useful in forming crosslinked polymer membranes with high permeance that are useful for the separation of fluid mixtures. Another method as described herein relates to making the crosslinked membranes from the high molecular weight, monoesterified polyimide polymer containing a small amount of bulky diamine. The small amount of bulky diamine allows for formation of both the high molecular weight polyimide polymer and for covalent ester crosslinks via reaction of the carboxylic acid groups with a diol crosslinking agent. This small amount of bulky diamines reduces chain mobility or segmental motion during crosslinking and reduces large loss of permeance. As such, this method provides a crosslinked membrane with good permeance and selectivity.
    Type: Grant
    Filed: December 23, 2015
    Date of Patent: August 1, 2017
    Assignees: Chevron U.S.A. Inc., Georgia Tech Research Corporation
    Inventors: Stephen Joseph Miller, William John Koros, Nanwen Li, Gongping Liu
  • Patent number: 9718033
    Abstract: One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. The polyimide polymers include monomers comprising dianhydride monomers, diamino monomers without carboxylic acid functional groups, and optionally diamino monomers with carboxylic acid functional groups, wherein 2 to 10 mole % of the diamino monomers are bulky diamino compounds and the ratio of diamino monomers with carboxylic acid functional groups to diamino monomers without carboxylic acid functional groups is 0 to 2:3. These uncrosslinked high molecular weight polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures.
    Type: Grant
    Filed: April 7, 2016
    Date of Patent: August 1, 2017
    Assignees: Chevron U.S.A. Inc., Georgia Tech Research Corporation
    Inventors: Stephen Joseph Miller, William John Koros, Nanwen Li, Gongping Liu
  • Patent number: 9718032
    Abstract: One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight, monoesterified polyimide polymer with a small amount of bulky diamine. These uncrosslinked high molecular weight, monoesterified polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight, monoesterified polyimide polymer with a small amount of bulky diamine. The small amount of bulky diamine allows for formation of a membrane comprising the uncrosslinked polymer that exhibits high permeance and good selectivity.
    Type: Grant
    Filed: April 7, 2016
    Date of Patent: August 1, 2017
    Assignees: Chevron U.S.A. Inc., Georgia Tech Research Corporation
    Inventors: Stephen Joseph Miller, William John Koros, Nanwen Li, Gongping Liu
  • Publication number: 20160214067
    Abstract: One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight polyimide polymer with a small amount of bulky diamine. The polyimide polymers include monomers comprising dianhydride monomers, diamino monomers without carboxylic acid functional groups, and optionally diamino monomers with carboxylic acid functional groups, wherein 2 to 10 mole % of the diamino monomers are bulky diamino compounds and the ratio of diamino monomers with carboxylic acid functional groups to diamino monomers without carboxylic acid functional groups is 0 to 2:3. These uncrosslinked high molecular weight polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures.
    Type: Application
    Filed: April 7, 2016
    Publication date: July 28, 2016
    Applicants: Chevron U.S.A. Inc., Georgia Tech Research Corporation
    Inventors: Stephen Joseph MILLER, William John KOROS, Nanwen LI, Gongping LIU
  • Publication number: 20160214066
    Abstract: One method as described herein relates to making a membrane comprising an uncrosslinked high molecular weight, monoesterified polyimide polymer with a small amount of bulky diamine. These uncrosslinked high molecular weight, monoesterified polyimide polymers with a small amount of bulky diamine are useful in forming polymer membranes with high permeance and good selectivity that are useful for the separation of fluid mixtures. Also as described herein is a hollow fiber polymer membrane comprising an uncrosslinked high molecular weight, monoesterified polyimide polymer with a small amount of bulky diamine. The small amount of bulky diamine allows for formation of a membrane comprising the uncrosslinked polymer that exhibits high permeance and good selectivity.
    Type: Application
    Filed: April 7, 2016
    Publication date: July 28, 2016
    Applicants: Chevron U.S.A. Inc., Georgia Tech Research Corporation
    Inventors: Stephen Joseph MILLER, William John KOROS, Nanwen LI, Gongping LIU
  • Publication number: 20160177034
    Abstract: One method as described herein relates to making a high molecular weight, monoesterified polyimide polymer using a small amount of bulky diamine. These high molecular weight, monoesterified polyimide polymers are useful in forming crosslinked polymer membranes with high permeance that are useful for the separation of fluid mixtures. Another method as described herein relates to making the crosslinked membranes from the high molecular weight, monoesterified polyimide polymer containing a small amount of bulky diamine. The small amount of bulky diamine allows for formation of both the high molecular weight polyimide polymer and for covalent ester crosslinks via reaction of the carboxylic acid groups with a diol crosslinking agent. This small amount of bulky diamines reduces chain mobility or segmental motion during crosslinking and reduces large loss of permeance. As such, this method provides a crosslinked membrane with good permeance and selectivity.
    Type: Application
    Filed: December 23, 2015
    Publication date: June 23, 2016
    Applicants: Chevron U.S.A. Inc., Georgia Tech Research Corporation
    Inventors: Stephen Joseph Miller, William John Koros, Nanwen Li, Gongping Liu