Radiation-grafted fuel cell membranes

Gubler L. Polymer design strategies for radiation-grafted fuel cell membranes. Adv Energy Mater 2014 4(3). 

Gubler L, Scherer GG (2008) Durability of radiation grafted fuel cell membranes. In Inaba M, Schmidt TJ, Buchi FN (eds) Proton exchange fuel cells durability. Springer,... 

Gubler, L., Slaski, M., Wallasch, F., Wokaun, A., Scherer, G.G. Radiation grafted fuel cell membranes based on co-grafting of a-methylstyrene and methacrylonitrile into a fluoropolymer base film. J. Membr. Sci. 339, 68-77 (2009)... 

Nasef, M.M., Saidi, H. (2002) Post-mortem analysis of radiation grafted fuel cell membrane using X-ray photoelecton spectroscopy. J. New Mater. Electrochem. Syst. 5, 183-189. 

Durability of Radiation-Grafted Fuel Cell Membranes... 

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. and Scherer, G.G. (2005d) A method for preparing a radiation grafted fuel cell membrane with enhanced chemical stability and a membrane electrode assembly, Patent Application W02006084591, Paul Scherrer Institut, Switzerland. 

Radiation-induced grafting and curing processes have been discussed in a number of reviews.203 28 291 The process is widely used for surface modification. Recent applications are the modification of fuel cell membranes and improving... 

Horsfall, J. A. and Lovell, K. V. 2001. Euel cell performance of radiation-grafted sulphonic acid membranes. Fuel Cells 1 186-191. 

A publication by the Paul Scherrer Institute reports progress in preparing membrane/electrode assemblies for polymer electrolyte fuel cells based on radiation-grafted FEP PSSA membranes [95]. Hot-pressing with Nation was used to improve the interfaces. These improved MEAs showed performance data comparable to those of MEAs based on Nafion 112 (Figure 27.58) and an service-life in H2/O2 fuel cells of more than 200 h at 60°C and 500 mA cm. ... 

An up-date of the status of EB curing of carbon fiber composites was presented by A. Berejka. Developments proven successful for aerospace applications are now being seriously scrutinized for automotive use. The diversity of proven uses of radiation grafting for uses in batteries, porous film and non-woven filters, and release coated films and papers was also presented. Opportunities for use of grafting in biomedical applications, composites technology, and fuel cell membrane development were also discussed. 

We have confined our goal to reviewing the state-of-the-art in the development of radiation grafted proton-exchange membranes. This review provides an up-to-date summary of the synthesis, properties, and appHcations of radiation grafted membranes as solid polymer electrolytes in fuel cells. 

Ion-exchange membranes based on radiation grafting technology are produced by Solvay. Different fluorinated polymers explored for fuel-cell membranes have been reviewed by Kostova et al. [164]. 

The significant contribution of Nafion or perfluorosulfonic membranes to the cost of the fuel cells stacks and the high alcohol crossover levels that affect the fuel efficiency, prompted the development of radiation grafted proton exchange membranes based on poly(ethylene-tetrafluoroethylene) (ETFE) [172-178], PVdF [175], andPTFE [179]. The peroxy radicals produced on the base polymer by y-ray, electron- or proton-beam, react with styrene to form a co-polymer that is then sulphonated. 

Nasef, M.M. 2008. Fuel cell membranes by radiation-induced graft copolymerization Current status, challenges, and future directions. In Polymer Membranes for Fuel Cells, eds. S.M.J. Zaidi and T. Matsuura, pp. 87-114. Springer Science New York. 

J.A. Horsfall, K.V. Lovell, Fuel cell performance of radiation grafted sulfonic acid membranes, Fuel Cells 1 (3 ) (2001) 186-191. 

Varcoe JR, Slade RCT, Yee ELH, Poynton SD, Driscoll DJ, Apperley DC (2007) Poly(ethylene-co-tetrafluoroethylene)-derived radiation-grafted anion-exchange membrane with properties specifically tailored for application in metal-cation-free alkaline polymer electrolyte fuel cells. Chem Mater 19(10) 2686-2693. doi 10.1021/cm062407u... 

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). 

T.A. Sherazi, J.Y. Sohn, YM. Lee, and M.D. Guiver, Polyethylene-based radiation grafted anion-exchange membranes for alkaline fuel cells, Journal of Membrane Science, 441, 148-157, 2013. 

Kiefer J., Brack H-P., Huslage J., Biichi F.N., Tsakada A., Geiga- F., and Schere G.G. (1999) Radiation grafting a versatile membrane preparation tool for fuel ceU applications. Proceedings of the European Fuel Cell Forum Portable Fuel Cells Conference, Lucerne, pp. 227-235. 

Fuel Cell Membranes by Radiation-Induced Graft Copolymerization Current Status, Challenges, and Future Directions... 

Strongly acidic (sulfonic acid) membranes have been identified for use as solid polymer electrolytes in fuel cells [28]. Preparation of these membranes by radiation induced graft copolymerization has been reported and reviewed in various occasions [23,24,27]. Historically, the first radiation grafted sulfonic acid membranes were prepared by Chen et al. [29] through grafting of styrene onto polyethylene (PE) films and used for battery separators and dialysis. However, most of the early woik on radiation-grafted membranes was carried out and reviewed by Chapiro [30]. 

Fuel Cell Membranes by Radiation-Induced Graft Copolymerization... 

Among fluorinated polymers, PTFE is the least polymer used for preparation of radiation-grafted membranes despite its extraordinary chemical, thermal, and mechanical stabilities. This is due to PTFE s extreme sensitivity to high-energy radiation, which produces chain scission with a very small irradiation dose [87], Nevertheless, studies on preparation of fuel cell membranes based on PTFE films were reported in literature [27]. 

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