3m Innovative Properties Company

Harold Todd Freemyer

Steven Joseph Hamrock

Michael Andrew Yandrasits

Gene H Shipman

Robert M Floyd

David G S Walton

Samantha D Smith

Klaus Hintzer

Kai Helmut Lochhaas

Michael K Domroese

David F Slama

Jonathan F Hester

Robert Steven Kody

Linda Mae Rivard

David J Colburn

George Gower Innes Moore

Tanja Zeif

Peter B Zenk

Shaped microporous articles are produced from polyvinylidene fluoride (PVDF) and nucleating agents using thermally induced phase separation (TIPS) processes. The shaped microporous article is oriented in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0. The shaped article may also comprise a diluent, glyceryl triacetate. The shaped microporous article may also have the micropores filled with a sufficient quantity of ion conducting electrolyte to allow the membrane to function as an ion conductive membrane. The method of making a microporous article comprises the steps of melt blending polyvinylidene fluoride, nucleating agent and glyceryl triacetate; forming a shaped article of the mixture; cooling the shaped article to cause crystallization of the polyvinylidene fluoride and phase separation of the polyvinylidene fluoride and glyceryl triacetate; and stretching the shaped article in at least one direction at a stretch ratio of at least approximately 1.1 to 1.0.

Microporous PVDF films

A polymer electrolyte membrane is provided having a thickness of 90 microns or less and comprising a polymer, said polymer comprising a highly fluorinated backbone and recurring pendant groups according to the formula:YOSO&#x2014;CF&#x2014;CF&#x2014;CF&#x2014;CF&#x2014;O-[polymer backbone]&#x2003;&#x2003;(I)where Y is Hor a monovalent cation such as an alkali metal cation. Typically, the membrane is a cast membrane. Typically, the polymer has a hydration product of greater than 22,000. Typically, the polymer has an equivalent weight of 800-1200.

Polymer electrolyte membrane

Anionic species are removed from aqueous dispersions of ionic fluoropolymers using anion exchange resins. In some embodiments, cationic species are also removed using cation exchange resins.

Method of purifying a dispersion of ionic fluoropolymer

The invention features integrated membrane assemblies for selectively transferring a constituent to or from a fluid. The assemblies include two or more flat sheet membrane elements and at least one common manifold connected to the interior regions of the membrane elements.

Membrane modules and integrated membrane cassettes

Growing community of inventors

Woodbury, MN, United States of America

Harold Todd Freemyer