Abstract: A perfluorinated ion exchange membrane useful for membrane electrode assemblies and fuel cells and having improved ionic conductivity and water absorption characteristics.

Abstract: Cation exchange membranes, made from polymer having cation exchange groups and containing inorganic filler, exhibit reduced fuel crossover for fuel cells employing direct feed organic fuels such as methanol and, when inorganic proton conductor is employed, enhanced proton conductivity.

Abstract: A hydrometallurgical process for treating copper feed materials containing gold and/or silver by simultaneously leaching copper, gold and/or silver into an aqueous cyanide solution, extracting copper, gold and cyanide with anion exchange resin is provided.

Abstract: An ion exchange film comprises a fluorine-containing polymer with (1) ion exchange sites present in a first layer as N-monosubstituted sulfonamido groups or salt thereof formed through reaction of a primary amine and (2) ion exchange sites present in a second layer of the film other than as said N-monosubstituted group or salt thereof. The film is suitable as a separator in a cell for electrolysis of an alkali or alkaline earth metal halide particularly sodium chloride in producing hydrogen, chlorine and caustic soda. In making concentrated caustic soda, high current efficiencies have been obtained in operation of the cell.

Abstract: An ion exchange film comprises a fluorine-containing polymer with (1) ion exchange sites present in a first layer as N-monosubstituted sulfonamido groups or salt thereof formed through reaction of a primary amine and (2) ion exchange sites present in a second layer of the film other than as said N-monosubstituted group or salt thereof. The film is suitable as a separator in a cell for electrolysis of an alkali or alkaline earth metal halide particularly sodium chloride in producing hydrogen, chlorine and caustic soda. In making concentrated caustic soda, high current efficiencies have been obtained in operation of the cell.

Abstract: Fluorinated cation exchange polymers are obtained from intermediate fluorinated polymers containing pendant sulfonyl halide groups which are reacted with a di- or polyamine and subjected to elevated temperature of the order of 170.degree. to 300.degree. C. The polymers are desirably employed with pendant side groups in the salt form. The polymers possess permselectivity giving desirable performance in electrolytic cells such as chlor-alkali cells as well as membrane ion exchanger and reverse osmosis devices.

Abstract: Fluorinated cation exchange polymers are obtained from intermediate fluorinated polymers containing pendant sulfonyl halide groups which are reacted with a di- or poly-amine and subjected to elevated temperature of the order of 170.degree. to 300.degree. C. The polymers are desirably employed with pendant side groups in the salt form. The polymers possess permselectivity giving desirable performance in electrolytic cells such as chlor-alkali cells as well as membrane ion exchanger and reverse osmosis devices.

Abstract: A cation permeable separator containing a polymer with ion exchange sites is reinforced with supporting fibers introduced into a polymer matrix in a fabric which also contains sacrificial fibers that are subsequently removed.In electrolysis of brine, the use of this type of reinforced cation permeable separator positioned between anode and cathode compartments of an electrolytic cell has resulted in increased electrical efficiency and/or decreased voltage.

Abstract: A woven fibrous ion-exchange fabric is initially formed from fibers as in the form of threads, ropes or yarns which comprise a fluorinated polymer with sulfonyl-containing pendant side chains in the --SO.sub.2 X form wherein X is fluorine or chlorine. Conversion of the sulfonyl group in the polymer to ionic form causes longitudinal shrinkage of the fiber in the woven fabric and lateral fiber swelling thereby forming an essentially impermeable fabric to physical flow of liquid through spaces between the fibers. High strength is realized in the woven fabric without a need for reinforcing material.

Abstract: Fluorinated cation exchange polymers are obtained from intermediate fluorinated polymers containing pendant sulfonyl halide groups which are reacted with a di- or polyamine and subjected to elevated temperature of the order of 170.degree. to 300.degree.C. The polymers are desirably employed with pendant side groups in the salt form. The polymers possess perm-selectivity giving desirable performance in electrolytic cells such as chlor-alkali cells as well as membrane ion exchanger and reverse osmosis devices.

Abstract: A woven or knitted fabric to be employed for ion exchange purposes comprises filaments of a fluorinated polymer with sulfonyl containing pendant side chains either in ionic or nonionic form whereby the filaments are supported by higher strength material prior to a weaving or knitting operation. Thereafter the supporting material is desirably removed. The final fabric may be woven so that the fabric is essentially impermeable to passage of fluids through fiber interstices or in an alternate manner is woven or knitted to allow controlled passage of liquid through fiber interstices. The polymer employed in the fabric possesses permselectivity giving desirable performance in electrolytic as well as membrane ion exchange and reverse osmosis devices.