Radiation-grafted fuel cell membranes grafting monomers

Fuel Cell Membranes by Radiation-Induced Graft Copolymerization Substituted styrene monomers ... 

Fig. 2 Monomers of the styrene family used in the preparation of radiation-grafted fuel cell membranes in different laboratories. The aromatic ring can be sulfonated, or the acid functionality may be incorporated via the R substituent...

Gubler, L., Slaski, M., Wokaun, A. and Scherer, G.G. (2006b) Advanced monomer combinations for radiation grafted fuel cell membranes. Electrochem. Commun. 8, 1215-1219. 

Furthermore, in 2001, Ballard entered an alliance with Victrex to produce two new membrane alternatives. One membrane is based on sulfonated poly(arylether) ketone (a variant of s-PEEK) supplied by Victrex, which may be better suited to PEM fuel cell fabrication applications. In March 2002, U.S. Patent 6359019 was issued to Ballard Power for a graft-polymeric membrane in which one or more trifluoro-vinylaromatic monomers are radiation graft polymerized to a preformed polymeric base. The structures of BAM membranes have been studied by way of small-angle neutron scattering or SANS. ° The study of the ionomer peak position suggests the existence of relatively small ionic domains compared to Nafion, despite large water content. Phase separation in the polymer matrix is possibly crucial for the manbrane s mechanical and transport properties. 

The service of membranes for fuel cells asks grafting of appropriate monomers for assuring catain electrical conductivity and stability [160-166]. The radiation processing of these systems is accomplished by the initiation of radical generation at low... 

Patents relating to the apphcation of radiation-grafted ion-exchange membranes in fuel cells have been granted to Scherer et al. [89] and to Stone and Stock [90, 91]. These patents mention the functionalization of base polymers with quaternary ammonium groups to yield alkaline polymers. The use of fluorine-substituted styrenic monomers is also claimed to improve membrane chemical stability when utilized in fuel cells (removal of undesired and reactive C-H bonds). 

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