Nafion reproducible processing

One of the challenges in processing Nafion is the frequent lack of reproducibility of physical properties. We suggested that the key to reproducible processing of Nafion is to control the clustering transition. By proper processing, we have been able to prepare reproducible materials, extruded and recast films have been produced with identical properties, and there is no memory of machine direction from the extrusion process [33, 43 5, 47]. 

The realization of the MEA is a crucial point for constructing a good fuel cell stack. The method currently used consists in hot-pressing (at 130 °C and 35 kg cm ) the electrode structures on the polymer membrane (Nafion). This gives non-reproducible results (in terms of interface resistance) and this is difficult to industrialize. New concepts must be elaborated, such as the continuous assembly of the three elements in a rolling tape process (as in the magnetic tape industry) or successive deposition of the component layers (microelectronic process) and so on. 

FIGURE 21.23 Synthesis process for Nafion membrane comonomer PSEPVE. (Reproduced from Doyle, M. and Rajendran, G., in Handbook of Fuel Cells Fundamentals, Technology and Applications, Vielstich, W., Gasteiger, H.A., and Lamm, A., eds., Vol. 3, John Wiley Sons, Chichester, U.K., 2003. With permission.)... 

Fig. 8 (a) Chemical structure of SPI with self-metallized silver electrodes, (b) schematic illustration of self-metallization process, (c) step responses of self-metallized SPI actuator and Nafion-based IPMC actuator under 0.5 V DC voltage (Song et al. 2011. 2011 WILEY-VCH Verlag GmbH Co. Reproduced by permission of John AViley Sons, Inc. All rights reserved.)... 

FIGURE 1.21 In situ solgel process for preparing Nafion/inorganic oxide nanoparticles hybrid composite membranes. (Reproduced with permission from Deng, Q. et al, J. Appl. Polym. Sci., 68, 747, 1998.)... 

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