Examples Nafion

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). 

Another design that is used in chlo-ralkali electrolysis, water electrolysis, and electro-organic synthesis [95-97] is the solid polymer electrolyte (SPE) cell, where an ion exchanger membrane, for example, Nafion , serves as the electrolyte, Fig. 9. The microporous catalytic reaction layers are pressed directly onto the membrane with porous current collectors allowing transport of dissolved reactants and gaseous products into and out of the reaction layer. 

Many acid-catalyzed reactions can be advantageously carried out using solid superacids instead of conventional acid systems. The reactions can be carried out in either the gaseous or the liquid phase. Using the example Nafion-H (a perfluoroalkane resin sulfonic acid, developed by DuPont) solid acid, several simple procedures were reported to carry out alkylation, transbromination, nitration, acetalization, hydration, and so on. 

In a hydrophilic ink, the CL binder is replaced with a hydrophilic perfluorosulfonate ionomer (PFSl, e.g., Nafion). It is well known that Nafion ionomer exists in different states according to the dielectric constants of solvents, e. For example, Nafion forms a solution in solvents with e > 10, a colloid in those with s between 3 and 10, and a precipitate in those with e < 3. Typically, a solution state with ethanol or isopropyl alcohol and a colloidal state with butyl acetate have been widely used in prior studies. 

More recently the advent of chemically modified electrodes, particularly polymer-modified electrodes, has greatly increased the scope of recognition and preconcentration modes available. For example, nafion [116]... 

The Poisson equation must be used if the electroneutrality condition does not hold, that is, when the relevant dimensions are not much larger than the Debye length. Examples include very thin membranes including bilayers " - and nanochannels. Mnltiple nanochannel structures may also occur in macroscopic ion-exchange membranes. For example, Nafion (tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octenesnlfonic acid copolymer) membranes with 20 vol.% of water have water channels with diameters between 1.8 and 3.5 nm. Also, the potentiometric response of nanoporous reference electrodes has been explained by the presence of nanopores. ... 

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