Patents by Inventor Wudneh Admassu

Wudneh Admassu 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).

  • Polycarbonate gas separation membranes containing substituted benzenes and processes for making and using the same
    Patent number: 4959082
    Abstract: This invention relates to improved semipermeable polycarbonate gas separation membranes containing substituted benzene(s), a method of using such membranes to separate gases, and a method of fabricating such membranes.
    Type: Grant
    Filed: July 20, 1989
    Date of Patent: September 25, 1990
    Assignee: The Dow Chemical Company
    Inventors: Wudneh Admassu, Daniel O. Clark
  • Semi-permeable hollow fiber gas separation membranes possessing a non-external discriminating region
    Patent number: 4955993
    Abstract: The invention is a semi-permeable hollow fiber gas separation membrane possessing a non-external discriminating region fabricated from hydrophobic polymeric materials possessing less than about 1 weight percent equilibrium water content at about 25.degree. C. The invention includes a process for making such membranes as well as a method of using such membranes.
    Type: Grant
    Filed: July 31, 1989
    Date of Patent: September 11, 1990
    Assignee: The Dow Chemical Company
    Inventors: Edgar S. Sanders, Jr., John A. Jensvold, Daniel O. Clark, Frederick L. Coan, Henry N. Beck, William E. Mickols, Peter K. Kim, Wudneh Admassu
  • Process for treating a liquid-wet polycarbonate membrane to improve its gas separation properties
    Patent number: 4900334
    Abstract: This invention relates to a method of treating liquid-wet polycarbonate membranes to improve gas separation properties.
    Type: Grant
    Filed: November 9, 1988
    Date of Patent: February 13, 1990
    Assignee: The Dow Chemical Company
    Inventors: Wudneh Admassu, John A. Jensvold, Daniel O. clark
  • Process for drying water-wet polycarbonate membranes
    Patent number: 4843733
    Abstract: The invention is a process for drying water-wet polycarbonate membranes by contacting the membrane with a pretreatment fluid containing at least one C.sub.1-4 alcohol to remove residual solvent and non-solvent and/or tighten the membrane discriminating layer, followed by drying the membrane with air or an inert gas to evaporate the alcohol and/or water.
    Type: Grant
    Filed: May 10, 1988
    Date of Patent: July 4, 1989
    Assignee: The Dow Chemical Company
    Inventor: Wudneh Admassu