Nafion/zeolite nanocomposite membranes

Chen Z, Hobnberg B, Li W, Wang X, Deng W, Munoz R, Yan Y (2006) Nafion/Zeolite nanocomposite membrane by in situ crystallization for a direct methanol fuel cell. Chem Mater 18 5669-5675... 

Gribov EN, Parkhomchuk EV, Krivobokov IM, Darr JA, Okunev AG (2007) Supercritical CO2 assited synthesis of highly selective nafion-zeolite nanocomposite membranes for direct methanol fuel cells. J Membr Sci 297 1-4... 

Chen et al. [30] reported fabrication of Nafion/zeolite nanocomposite man-branes by hydrothermal growth of acid-functionalized zeolite nanocrystals into commercial Nafion membranes for DMFCs. The presence of zeolite nanocrystals in the composite is confirmed by X-ray diffraction techniques. The tensile strength and water uptake were studied and the performance was compared with that of the... 

Fig. 6 Illustration of Nafion-acid functionalized zeolite Beta nanocomposite membranes helping to increase the proton conductivity and decrease the methanol crossover (A) H2O and CH3OH diffusion reduced by zeolite flow resistance (B) sulphonic acid functionalized zeolite nanoparticles increases proton conductivity of composite membranes. (View this art in color at www. dekker. com.)...

Holmberg, B.A. Wang, H. Norbeck, J.M. Yan, Y. Nafion/acid functionalized zeolite nanocomposite fuel cell membranes. Polym. Prepr. (Am. 

Polyaniline (PANI) nanocomposite membranes are also prepared by a sol-gel process, embedding silica in the hydrophilic clusters (Nafion) followed by its deposition by redox polymerization [51]. PANI modified the membrane structure and reduced the methanol crossover, while silica Incorporation improved the conductivity and stability. Zeolite has been incorporated as potential filler for PEMs, either by blending or by infiltration in swelled membrane, to reduce the methanol permeability and enhance the thermal stabihty [52,53]. Although the fuel cell performance of these membranes was Inferior compared with pristine Nafion membrane, incorporation of semipermeable particles is an effective method to engineer the transport properties of composite membranes. Chen et al [54] reported nanocomposite membranes by in situ hydrothermal crystallization method, with similar proton conductivity, but low methanol permeability (40% less) in comparison with Nafion membrane. These membranes showed higher OCV (3%) and power density (21%) than Nafion. 

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