Nafion polymers, polymer exchange membranes

For the continuous process, a special divided cell (Pb02/steel anode, steel cathode, Nafion as cation exchange membrane) based on the principle of a tubular reactor was developed. The final product can be removed in gaseous form, so that the electrolyte can be recycled in a simple manner. The membrane and electrodes are supposed to have lifetimes of at least one year 63). Hexafluoropropylene is a useful monomer for fluorine-containing polymers, e.g., fluorinated polyethers. 

This is also called the Solid Polymer Fuel Cell (SPFQ and the Direct Methanol Fuel Cell (DMFC) is included in this classification. These cells use a solid perfluorinated sulfonated polymer ion exchange membrane (e.g. DuPont Nafion) [65] in the form of a thin plastic film, which serves as the electrolyte in the PEM fuel cell operating at 50-100°C. 

Yuan, J.J., Pu, H.T., Yang, Z.L. (2009) Studies on sulfonic add functionahzed hollow sihca spheres/Nafion composite proton exchange membranes. Journal of Polymer Science Part A Polymer Chemistry, AH, 2647-2655. 

To keep the consumption of the valuable platinum low, thin foils have been glued to a graphite support [34] or thin-layers of platinum have been sputtered on to a glass base [59]. Platinum can be used in a particle electrode by plating silica gel with platinum [60], or in a solid polymer electrolyte where platinum is incorporated into a nafion ion exchange membrane [61]. 

PEM Proton-exchange-membrane fuel cell (Polymer-electrolyte-membrane fuel cell) Proton- conducting polymer membrane (e.g., Nafion ) H+ (proton) 50-80 mW (Laptop) 50 kW (Ballard) modular up to 200 kW 25-=45% Immediate Road vehicles, stationary electricity generation, heat and electricity co-generation, submarines, space travel... 

The potential use of polymeric ion-exchange membranes in the next generation single-ion secondary lithium polymer batteries was shown by Sachan et al 84,85 Conductivities exceeding 10 S/cm with transference numbers of unity were achieved for Nafion converted to the Li+ salt form. 

Proton exchange membrane fuel cell (PEMFC) working at around 70 °C with a polymer membrane electrolyte, such as Nafion, which is a solid proton conductor (conducting by the H + cation). 

Perfluorosulfonic acid polymers, for example, Nafion, or ionic and cross-linked polystyrene derivatives, are the best known examples of ion-exchange membrane materials (see also Section 2.6.4). 

See also -> ions-exchange membrane, -> Nafion , -> poly electrolytes, -> polymer electrolytes. 

The proton exchange membranes (PEMs) used in PEM fuel cells consist of two domains the hydrophobic polymer backbone domain and the hydrophilic ionic cluster domain. The most commonly used membrane is Nafion , produced by DuPont. 

The /J-sultone formed in the reaction of sulfur trioxide with tetrafluoroethenc itself is a key intermediate in the synthesis of Nafion polymers, which have commercial use as ion-exchange membranes. Furthermore, perfluorovinylsulfonyl fluoride (3) is transformed into mainly the /Tsultone 4 when heated with sulfur trioxide at elevated temperature. ... 

Figure 3.42. Segment of a perfluorinated sulphonate ion exchange membrane of Nafion t) e. The top polymer chain is made from C atoms as backbone and pairs of F atoms on the sides (end hydrogens are replaced when the chain is enlarged). The acid FISOj molecule promoting H transport is attached at the end of an arm of 4 CFj molecules interspersed with two O atoms, and with one F replaced by a CFj group.

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