Patents by Inventor Stephen A. Rholl

Stephen A. Rholl 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).

  • Dilution stable water based magnetic fluids
    Patent number: 4208294
    Abstract: A dilution stable water based magnetic fluid is provided by dispersing magnetic particles in water with the aid of a C.sub.10 -C.sub.15 aliphatic monocarboxylic acid. The magnetic particles are preferably particles of magnetite, prepared by precipitation of dissolved iron chloride salts from aqueous solution by the use of ammonium hydroxide. The preferred acids used in preparing the dispersions are dodecanoic (C.sub.12) and tridecanoic (C.sub.13).
    Type: Grant
    Filed: February 12, 1979
    Date of Patent: June 17, 1980
    Assignee: The United States of America, as represented by the Secretary of the Interior
    Inventors: Sanaa E. Khalafalla, George W. Reimers, Stephen A. Rholl