Poly-ethylene tetrafluoroethylene-based membranes

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. 

Brack HP, Biichi FN, Huslage J, Rota M, Scherer GG (2000) Development of radiation grafted membranes for fuel cell applications based on poly(ethylene-aZt-tetrafluoroethylene). In Pinnau I, Freeman BD (eds) Membrane formation and modification. ACS symposium series 744. Oxford University Press, New York, p 174 Brack HP, Scherer GG (1997) Macromol Symp 126 25 Brack HP, Biihrer HG, Bonorand L, Scherer GG (2000) J Mater Chem 10 1795 Walsby N, Sundholm F, KaUio T, Sundholm G (2001) J Polym Sci A 39 3008 Lee W, Shibasaki A, Saito K, Sugita K, Okuyama K, Suyo T (1996) J Electrochem Soc 143 2795... 

The acid-base Nafion composite membranes include blends of Nafion with polypyrrole (PPy) [98-104], polybenzimidazole (PBI) [105-107], poly (propyleneoxide) (PPO) [108, 109], polyfurfuryl alcohol (PFA) [110], poly(vinyl alcohol) (PVA) [111-115], sulfonated phenol-formaldehyde (sPF) [116], polyvinylidene fluoride (PVdF) [117-122], poly(p-phenylene vinylene) (PPV) [123], poly(vinyl pyrrolidone) (PVP) [124] polyanifine (PANI) [125-128], polyethylene (PE) [129], poly(ethylene-terephtalate) [130], sulfated p-cyclodextrin (sCD) [131], sulfonated poly(ether ether ketone) (sPEEK) [132-135], sulfonated poly(aryl ether ketone) (sPAEK) [136], poly(arylene ether sulfone) (PAES) [137], poly(vinylimidazole) (PVl) [138], poly(vinyl pyridine) (PVPy) [139], poly (tetrafluoroethylene) (PTFE) [140-142], poly(fluorinated ethylene-propylene) [143], sulfonated polyhedral oligomeric silsesquioxane (sPOSS) [144], poly (3,4-ethylenedioxythiophene) (PEDT) [145, 146], polyrotaxanes (PR) [147], purple membrane [148], sulfonated polystyrene (PSSA) [149, 150], polystyrene-b-poly(ethylene-ran-butylene)-bpolystyrene (SEES) [151], poly(2-acrylamido-2-methyl-l-propanesulphonic acid-co-l,6-hexanediol propoxylate diacrylate-co-ethyl methacrylate) (AMPS) [152], and chitosan [31]. A binary PVA/chitosan [153] and a ternary Nafion composite with PVA, polyimide (PI) and 8-trimethoxy silylpropyl glycerin ether-1,3,6-pyrenetrisulfonic acid (TSPS) has also been reported [154]. 

T. Tran Duy, S.I. Sawada, S. Hasegawa, Y. Katsumura, Y. Maekawa, Poly(ethylene-co-tetrafluoroethylene)(ETFE)-based graft-type polymer electrolyte membranes with different ion exchange capacities relative humidity dependence for fuel cell applications, J. Membr. Sci. 447 (2013) 19-25. 

H.P. Brack, F.N. Btichi, M. Rota and G.G. Scherer, Development of radiation-grafted membranes for fuel ceU applications based on poly(ethylene-alt-tetrafluoroethylene), Polym. Mater. Sci. Eng. 77, 368 (1997). 

Varcoe, J.R., Slade, R.C., Lam How Yee, E., Poynton, S.D., Driscoll, D.J., Apperley, D. C. (2007) Poly(ethylene-co-tetrafluoroethylene)-derived radiation-grafted anion-exchange membrane with properties specifically tailored for application in metal-cat-ion-free alkaline polymer electrolyte fuel cells. Chemistry of Materials, 19, 2686-2693. Slade, R.C., Varcoe, J.R. (2005) Investigations of conductivity in FEP-based radiation-grafted alkaline anion-exchange membranes. Solid State Ionics, Y16, 585-597. 

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