The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 19, 2002
Filed:
Nov. 12, 1997
Charles Stone, Vancouver, CA;
Alfred E. Steck, West Vancouver, CA;
Ballard Power Systems Inc., Burnaby, CA;
Abstract
Graft polymeric membranes in which one or more trifluorovinyl aromatic monomers are radiation graft polymerized to a preformed polymeric base film are provided, as well as ion-exchange membranes prepared therefrom. Preferred monomers include substituted &agr;, &bgr;, &bgr;-trifluorostyrenes and trifluorovinyl naphthalenes which are activated towards the grafting reaction or facilitate the introduction of more than one ion-exchange group per monomer unit in the grafted chains. The ion-exchange membranes are useful in dialysis applications, and particularly in electrochemical applications, for example as membrane electrolytes in electrochemical fuel cells and electrolyzers.