Patents by Inventor Robert Zepf
Robert Zepf 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).
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Publication number: 20050011834Abstract: The present invention relates to the field of synthetic polymeric microfiltration membrane materials that are fabricated to separate liquids from solids contained therein. One aspect of the invention relates to a highly asymmetric, hydrophilic microfiltration membrane with high surface porosity. The membrane is rendered hydrophilic through co-casting the sulfone polymer with a hydrophilic polymer, such as polyvinylpyrrolidone. The membranes of the invention are highly useful in testing devices for the quick detection of properties or components contained in liquid samples, such as diagnostic applications, as well as for other filtration applications that demand relatively large pore sizes, thick membranes, high asymmetry, and/or high lateral wicking speeds.Type: ApplicationFiled: August 16, 2004Publication date: January 20, 2005Inventors: I-Fan Wang, Richard Morris, Robert Zepf
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Patent number: 6565748Abstract: The present invention relates to cationically charge-modified membranes and methods of preparing such membranes. In one major aspect of the invention, the membranes are hydrophobic membranes that are treated with one or more polymeric wetting agents to render the membranes substantially hydrophilic, followed by treatment with one or more charge-modifying agents, the agents causing the membranes to possess a fixed formal positive charge. In another major aspect of the invention, a cationic membrane is formed from casting in a film a mixed polymer solution comprising a sulfone polymer and a copolymer of vinylpyrrolidone and a cationic imidazolinium compound, and quenching the film in an aqueous bath to produce a coagulated membrane. The membrane can be further cationically charge-modified with one or more charge-modifying agents.Type: GrantFiled: January 14, 2000Date of Patent: May 20, 2003Assignee: Pall CorporationInventors: I-fan Wang, Robert Zepf
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Patent number: 6440306Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.Type: GrantFiled: January 25, 2000Date of Patent: August 27, 2002Assignee: Pall CorporationInventors: Jerome Ditter, Richard A. Morris, Robert Zepf
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Patent number: 6277281Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.Type: GrantFiled: May 15, 2000Date of Patent: August 21, 2001Assignee: USF Filtration and Separations Group Inc.Inventors: Jerome Ditter, Richard A. Morris, Robert Zepf
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Patent number: 6146747Abstract: The present invention relates to the field synthetic polymeric membrane materials formed from casting polyvinylidene difluoride (PVDF) polymer solutions and/or dispersions. Membranes formed in accordance with the present invention are all highly porous. Both internally isotropic membranes and highly asymmetric PVDF membranes are disclosed. Membranes of the invention may be hydrophobic or hydrophilic. The membranes of the invention are useful in a variety of microfiltration and ultrathin applications.Type: GrantFiled: May 18, 1998Date of Patent: November 14, 2000Assignee: USF Filtration and Separations Group Inc.Inventors: I-Fan Wang, Jerome F. Ditter, Robert Zepf
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Patent number: 6110369Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.Type: GrantFiled: July 29, 1997Date of Patent: August 29, 2000Assignee: USF Filtration and Separations Group, Inc.Inventors: Jerome Ditter, Richard A. Morris, Robert Zepf
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Patent number: 6110309Abstract: The present invention relates to the field synthetic polymeric membrane materials formed from casting polyvinylidene difluoride (PVDF) polymer solutions and/or dispersions. Membranes formed in accordance with the present invention are all highly porous. Both internally isotropic membranes and highly asymmetric PVDF membranes are disclosed. The membranes of the invention are useful in a variety of microfiltration and ultrathin applications.Type: GrantFiled: August 20, 1998Date of Patent: August 29, 2000Assignee: USF Filtration and Separations Group, Inc.Inventors: I-Fan Wang, Jerome F. Ditter, Robert Zepf
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Patent number: 6045694Abstract: The present invention relates to cationically charge-modified membranes and methods of preparing such membranes. In one major aspect of the invention, the membranes are hydrophobic membranes that are treated with one or more polymeric wetting agents to render the membranes substantially hydrophilic, followed by treatment with one or more charge-modifying agents, the agents causing the membranes to possess a fixed formal positive charge. In another major aspect of the invention, a cationic membrane is formed from casting in a film a mixed polymer solution comprising a sulfone polymer and a copolymer of vinylpyrrolidone and a cationic imidazolinium compound, and quenching the film in an aqueous bath to produce a coagulated membrane. The membrane can be further cationically charge-modified with one or more charge-modifying agents.Type: GrantFiled: July 8, 1997Date of Patent: April 4, 2000Assignee: USF Filtration and Separations Group, Inc.Inventors: I-fan Wang, Robert Zepf
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Patent number: 5979670Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.Type: GrantFiled: June 11, 1997Date of Patent: November 9, 1999Assignee: USF Filtration and Separations Group Inc.Inventors: Jerome Ditter, Richard A. Morris, Robert Zepf
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Patent number: 5846422Abstract: Highly asymmetric polymeric membranes with large pores which yield bubble points in the range of 0.5 to 25 psid and superior flow characteristics. The membranes can be cast from both metastable dispersions and from homogenous casting formulations. The technique of synthesis involves exposure of the cast membrane to humid air to create large surface pores on the exposed side.Type: GrantFiled: June 11, 1996Date of Patent: December 8, 1998Assignee: Memtec America CorporationInventors: Jerome Ditter, Richard A. Morris, Robert Zepf
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Patent number: 5834107Abstract: The present invention relates to the field synthetic polymeric membrane materials formed from casting polyvinylidene difluoride (PVDF) polymer solutions and/or dispersions. Membranes formed in accordance with the present invention are all highly porous. Both internally isotropic membranes and highly asymmetric PVDF membranes are disclosed. The membranes of the invention are useful in a variety of microfiltration and ultrathin applications.Type: GrantFiled: January 22, 1997Date of Patent: November 10, 1998Assignee: USF Filtration and Separations Group Inc.Inventors: I-Fan Wang, Jerome F. Ditter, Robert Zepf