Patents by Inventor Irving Joffee

Irving Joffee 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).

  • Uniform polyvinylidene difluoride membranes
    Patent number: 5198505
    Abstract: A heat-treated, hydrophobic, polyvinylidene difluoride membrane is provided having uniform crystallinity as evidenced by a difference in crystallinity over the membrane of less than about 10 percent. Also provided is a hydrophilic, polyvinylidene difluoride membrane prepared from a heat-treated, hydrophobic, polyvinylidene difluoride membrane which remains hydrophilic after heating to a temperature as high as about 121.degree. C.
    Type: Grant
    Filed: April 11, 1991
    Date of Patent: March 30, 1993
    Assignee: Pall Corporation
    Inventors: Ioannis P. Sipsas, Isaac Rothmann, Irving Joffee
  • Method for making uniform polyvinylidene difluoride membranes
    Patent number: 5196508
    Abstract: A method is provided for enhancing the characteristics of a hydrophobic polyvinylidene difluoride membrane which comprises heating the membrane to a temperature of at least 80.degree. C. but less than the temperature at which the membrane softens and deforms for a time sufficient to achieve a state such that, when the membrane is subsequently hydrophilized, the membrane has substantially uniform hydrophilic properties.
    Type: Grant
    Filed: June 6, 1991
    Date of Patent: March 23, 1993
    Assignee: Pall Corporation
    Inventors: Ioannis P. Sipsas, Isaac Rothmann, Irving Joffee