Patents by Inventor Marinda L. Wu

Marinda L. Wu 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).

  • Patent number: 4789386
    Abstract: The invention relates to improved gas separation membranes fabricated from a polymer containing a hydrocarbon backbone and pendant metal ionomer groups wherein the pendant metal ionomer groups contain cations of alkali metals, alkaline earth metals, or transition metals bound to pendant --CO.sub.2.sup.-. The metal modified membranes result in improved gas selectivities with comparable or improved permeabilities over the unmodified membranes. The membranes may be used to separate gas mixtures such as carbon dioxide and methane or oxygen and nitrogen.
    Type: Grant
    Filed: September 18, 1986
    Date of Patent: December 6, 1988
    Assignee: The Dow Chemical Company
    Inventors: Walter L. Vaughn, Marinda L. Wu
  • Patent number: 4749414
    Abstract: The invention relates to a composition useful for producing a modifying adherent layer on a passive polymeric material, said composition comprising (A) a fluorinated ester substituted alkoxy cellulose having, on the average, between about 1.0 to 2.99 of the three reactive hydroxyl groups of each glucose unit present as alkoxy groups, and the remainder of the reactive hydroxyl groups of each glucose unit present as a fluoroester group of the formula: ##STR1## wherein R.sub.f is branched perfluoroalkyl comprising 3 to 20 carbon atoms; or --(CF.sub.2).sub.n CF.sub.2 --Q, wherein Q is hydrogen of fluorine; n is an integer from 1 to 19; or ##STR2## wherein X is selected from the group consisting of --F, --CF.sub.3 and --CF.sub.2 Cl, Y is --F, --Cl, --CF.sub.2 Cl or perfluoroalkyl having from 1 to 10 carbon atoms, Z is --F, --Cl, --CF.sub.3 or CF.sub.2 Cl, and m is an integer from 1 to 12; and (B) an organic solvent.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: June 7, 1988
    Assignee: The Dow Chemical Company
    Inventors: Marinda L. Wu, John F. Voeks
  • Patent number: 4741744
    Abstract: The invention relates to a process of separating gases using a membrane fabricated from a polymer containing a perfluorinated backbone and pendant hydrated metal ionomer groups wherein the pendant hydrated metal ionomer groups contain cations of alkali metals, alkaline earth metals, or transition metals bound to SO.sub.3.sup.-. The hydrated membranes have improved gas permeabilities with comparable gas selectivities over the unhydrated membranes. The membranes may be used to separate gas mixtures containing such gases as carbon dioxide and methane.
    Type: Grant
    Filed: February 20, 1987
    Date of Patent: May 3, 1988
    Assignee: The Dow Chemical Company
    Inventors: Marinda L. Wu, Terry D. Gordon, Charles W. Martin
  • Patent number: 4695295
    Abstract: The invention relates to improved gas separation membranes fabricated from cyclic iminoether modified alpha-olefin/carboxylic acid copolymers. The modified membranes possess improved gas selectivities and/or permeabilities over the unmodified membranes. The membranes may be used to separate gas mixtures containing such gases as oxygen, nitrogen, methane, and carbon dioxide.
    Type: Grant
    Filed: September 24, 1986
    Date of Patent: September 22, 1987
    Assignee: The Dow Chemical Company
    Inventors: Linneaus C. Dorman, Victor E. Meyer, Marinda L. Wu
  • Patent number: 4666468
    Abstract: The invention is a method of separating a gas comprising helium, oxygen, nitrogen or carbon dioxide from a mixture of gases containing helium, oxygen, nitrogen or carbon dioxide wherein the method comprisesA. contacting the gas mixture with a thin, non-porous membrane comprising a polymer with a perfluorinated backbone and pendant ionomer moieties which contain cations of alkali metals, alkaline earth metals, or transition metals under conditions such that helium, oxygen, nitrogen or carbon dioxide selectively permeates through the membrane to the other side of the membrane; and,B. removing the permeated helium, oxygen, nitrogen or carbon dioxide from the other side of the membrane.The membranes useful in the method of this invention demonstrate good selectivity for oxygen, helium, nitrogen, and carbon dioxide over other gases in gas mixtures containing such gases. Furthermore, the permeabilities of oxygen, helium, and carbon dioxide through these membranes is quite good.
    Type: Grant
    Filed: March 24, 1986
    Date of Patent: May 19, 1987
    Assignee: The Dow Chemical Company
    Inventor: Marinda L. Wu
  • Patent number: 4664978
    Abstract: This invention relates to an improved process to produce composite polymeric materials and an article having an adherent surface layer. More specifically, the invention describes a process for producing a modifying adherent layer on a passive polymeric material, the layer comprising a fluorinated ester substituted alkoxy cellulose having, on the average, between about 1.0 to 2.99 of the three reactive hydroxyl groups of each glucose unit present as alkoxy groups, and the remainder of between about 0.01 to 2.00 of the reactive hydroxyl groups of each glucose unit present as a fluoroester group of the formula: ##STR1## wherein R.sub.f is branched perfluoroalkyl comprising 3 to 20 carbon atoms; or --(CF.sub.2).sub.n CF.sub.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: May 12, 1987
    Assignee: The Dow Chemical Company
    Inventors: Marinda L. Wu, John F. Voeks
  • Patent number: 4403742
    Abstract: A dramatic reduction in the time required to fine-grind high borate solder glasses is achieved. In the prior art method, the glass is ball-milled in the presence of an amine for about seven days or more. It has now been discovered that by first rod-milling such glasses for a period of from about 1/2 to about 24 hours, the time required for the "amine grind" can be shortened to a period of from about 1 to 3 days. A further improvement is that rod milling eliminates the laborious sieving procedure previously employed to ensure the absence of undesirably large particles in the feed to the amine grinding operation.
    Type: Grant
    Filed: November 13, 1980
    Date of Patent: September 13, 1983
    Assignee: The Dow Chemical Company
    Inventor: Marinda L. Wu