Abstract: A method is described for precious metal recovery from acidic precious metal-cyanide solutions by means of a weakly-basic anion-exchange material comprising a polymeric felt incorporating radiation-grafted pyridinyl functional groups.

Abstract: This disclosure is directed to improved redox type electrochemical cells, preferably those of the iron (+3)/iron (+2) electrolyte variety, incorporating polymeric, ion-exchange separator membranes produced by radiation grafting techniques.

Abstract: A method for manufacturing tubular shaped thermoplastic members comprising conveying two thin sheets of thermoplastic material in close substantially parallel relationship through an ultrasonic welding station for forming a plurality of continuous spaced apart seams substantially parallel to the direction of conveying for joining the two sheets of thermoplastic material. The seams, thus formed, are cut substantially parallel to the direction of conveying such that the two sheets of thermoplastic material remain joined adjacent each side of the cuts. Preferably, the cutting takes place substantially simultaneously with the ultrasonic formation of the seams and the thin sheets of thermoplastic material are cooled prior to the ultrasonic welding. An apparatus for practicing the method is also disclosed. The method and apparatus are particularly adaptable for the manufacture of ionically permeable thermoplastic separators for use in electrochemical cells and the like.

Abstract: This invention relates to an irradiation grafting process for preparing separator membranes for use in electrochemical cells, comprising contacting a polymeric base film with an aqueous solution of a hypophilic monomer and a polymerization retardant; and irradiating, said contacted film to form a graft membrane having low electrical resistivity and having monomer molecules uniformly grafted thereon.

Abstract: This disclosure is directed to polymer membranes to be used in electrochemical cells and improved processes for producing the same. The membranes are produced by radiation grafting techniques. The improved process includes the grafting of a hydrophilic monomer, such as methacrylic acid in a chlorinated organic solvent onto an inert base film such as polyethylene. The process also includes but is not limited to the use of inhibitors to limit homopolymerization of a grafting material, as well as emulsifying agents to lower the electrolytic resistance of the finished membrane.

Abstract: This disclosure is directed to fluorocarbon polymers, polymeric membranes, and electrochemical cells and processes. The polymers and membranes are produced by radiation techniques to provide improved products. For example, .alpha.,.beta.,.beta.-trifluorostyrene in an inert organic solvent is grafted onto an inert film, such as tetrafluoroethylene-hexafluoropropylene copolymer, by irradiation, i.e. with Co-60 gamma radiation at a dose of several Mrad. The grafted film is then sulfonated, preferably in a chlorosulfonic acid bath. The resulting film is useful as a membrane or diaphragm in various electrochemical cells such as chlor-alkali or fuel cells.

Abstract: This disclosure is directed to fluorocarbon polymers, polymeric membranes, and electrochemical cells and processes. The polymers and membranes are produced by radiation techniques to provide improved products. For example, .alpha., .beta., .beta.-trifluorostyrene in an inert organic solvent is grafted onto an inert film, such as tetrafluoroethylene-hexafluoropropylene copolymer, by irradiation, i.e. with Co-60 gamma radiation at a dose of several Mrad. The grafted film is then sulfonated, preferably in a chlorosulfonic acid bath. The resulting film is useful as a membrane or diaphragm in various electrochemical cells such as chlor-alkali or fuel cells.

Abstract: This disclosure is directed to fluorocarbon polymers, polymeric membranes, and electrochemical cells and processes. The polymers and membranes are produced by radiation techniques to provide improved products. For example, .alpha.,.beta.,.beta.-trifluorostyrene in an inert organic solvent is grafted onto an inert film, such as tetrafluoroethylene-hexafluoropropylene copolymer, by irradiation, i.e. with Co-60 gamma radiation at a dose of several Mrad. The grafted film is then sulfonated, preferably in a chlorosulfonic acid bath. The resulting film is useful as a membrane or diaphragm in various electrochemical cells such as chlor-alkali or fuel cells.

Abstract: This disclosure is directed to polymer membranes to be used in electrochemical cells and improved processes for producing the same. The membranes are produced by radiation grafting techniques. The improved process includes the grafting of a hydrophilic monomer, such as methacrylic acid in a chlorinated organic solvent onto an inert base film such as polyethylene. The process also includes but is not limited to the use of inhibitors to limit homopolymerization of a grafting material, as well as emulsifying agents to lower the electrolytic resistance of the finished membrane.