Protic membrane preparation

Eguizabal A, Lemus J, Roda V et al (2012) Nanostmctured electrolyte membranes based on zeotypes, protic ionic liquids and porous PBl membranes preparation, characterization and MEA testing. Int J Hydrogen Energy 37 7221-7234... 

This starting material is prepared in three steps from commercially available (from Research Organic/Inorganic Chemical Corp., Belleville, NJ) 3,4-methylenedioxyphenylacetic acid according to well-established procedures that have been applied to similar compounds. First, 16.0 g (88.8 mmol) of the acid, recrystallized from chloroform, is dissolved in 50 mL of tetra-hydrofuran, and the solution is added to a suspension of 5.98 g (158 mmol) of lithium aluminum hydride powder in 225 ml of distilled diethyl ether (Note 3) at 0°C. [Caution Lithium aluminum hydride ie very sensitive to mechanical shock, and very reactive towards moisture and other protic substances its dust is very irritating to skin and mucous membranes. It should not be allowed to come into contact with metallic species or apparatus, including metal... 

Since only Ta and Nb catalysts, which are not tolerant to polar groups, are available for the polymerization of disubstituted acetylenes, it is generally difficult to synthesize disubstituted acetylene polymers having protic and/or highly polar substituents such as hydroxy, carboxy, and sulfonic acid groups. In order to obtain polar group-containing polymers of disubstituted acetylenes, recently polymer reactions have been employed. Polymer reactions have proved useful also in the preparation of poly(DPA) membrane, namely, while the... 

Moreover, sulfonated polyimides (SPIs) have been used to prepare polymer electrolyte manbranes for nonhumidified fuel cells by the addition of a protic ionic liquid, diethylmethylammonium trifluoromethanesulfonate [demaJCCFjSOs] (See Fig. 9.6) [78, 79]. The uniform, tough, and transparent membranes have good thermal stability (>300 °C) and ionic conductivity (>10 S cm with an ionic liquid content higher than 67 %) under anhydrous conditions. A current density higher than 240 mA cm is achieved with a maximum power density of 100 mW cm at 80 °C when using a membrane in the H2/O2 fuel cell operation under dry conditions. 

Fig. 6. Protic ILs employed to prepared proton conducting membranes via the polymerization of microemulsions.

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