Amtek Research International LLC

James E Emanuel

Richard W Pekala

Weston J Wood

Daniel K Lee

Andrew Wimer

Robert R Waterhouse

James Phillip Young

Chi Thuong-Le La

Matthew Alan Warren

Robert Waterhouse

A thin, freestanding, microporous polyolefin web with good heat resistance and dimensional stability includes an inorganic surface layer. A first preferred embodiment is a microporous polyolefin base membrane in which colloidal inorganic particles are present in its bulk structure. Each of second and third preferred embodiments is a thin, freestanding microporous polyolefin web that has an inorganic surface layer containing no organic hydrogen bonding component for the inorganic particles. The inorganic surface layer of the second embodiment is achieved by hydrogen bonding with use of an inorganic acid, and the inorganic surface layer of the third embodiment is achieved by one or both of hydrogen bonding and chemical reaction of the surface groups on the inorganic particles.

Freestanding, dimensionally stable microporous webs

A polymer fiber sheet exhibits high porosity and good tensile properties in both 'wet' and 'dry' states. A fiber modifying agent is incorporated into a polymer extrusion and fiber formation process to produce a highly porous polymer fiber sheet that is instantaneously wettable by an aqueous medium. The fiber modifying agent functions as either one or both (1) a plasticizer that reduces the polymer extrudate melt viscosity and allows the formation of fine fibers during processing and (2) a surface modifying agent that promotes the instantaneous and sustainable wettability of individual polymer fibers and a porous fiber sheet formed from them. The polymer fiber sheet maintains its wettability even after repeated washing and drying cycles. The resultant fiber sheet can be densified and embossed to provide a desired thickness and porosity, while at the same time longitudinal ribs with desired pattern can also be formed on the fiber sheet.

Instantaneously wettable polymer fiber sheet

A freestanding, microporous polymer sheet ( ) is composed of a polymer matrix binding and electrically conductive matrix. The polymer matrix preferably includes UHMWPE, and the electrically conductive matrix preferably is in powder form. The UHMWPE is of a molecular weight that provides sufficient molecular chain entanglement to form a sheet, with freestanding characteristics. Multiple microporous sheets ( ) can be wound or stacked in a package filled with an electrolyte to function as electrodes in an energy storage device ( ), such as a battery. Metallic layers ( ) can be applied to the microporous sheets to function as current collectors in such devices.

Electrically conductive, freestanding microporous polymer sheet

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Corvallis, OR, United States of America

James E Emanuel