Patents by Inventor Catherine C. Johnson

Catherine C. Johnson 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).

  • Reverse osmosis membrane of high urea rejection properties
    Patent number: 4199448
    Abstract: Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source and forming a polymeric membrane by depositing a polymer of said unsaturated monomer from said plasma onto a substrate, such that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.
    Type: Grant
    Filed: June 9, 1976
    Date of Patent: April 22, 1980
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Catherine C. Johnson, Theodore J. Wydeven