F Cell Cars

by Dominic’s pics

Article by Uriahyang

Imidazole and 1-methylimidazole (Me-Im) were used as additives in polybenzimidazole (PBI) equilibrated with phosphoric acid (PA), a system shown to be a high-temperature proton-conducting polymer electrolyte. The influence of different concentrations of this additive on the conductivity of these membranes was measured by a four-probe conductivity measurement, at temperatures in the range of 80 200 degree C, under various humidity conditions. Correlation was found between the conductivity of liquid solutions of concentrated phosphoric acid and that of H3PO4 in the PBI membranes.

1-Methylimidazole(Molecular formula:C4H6N2) is a derivative of imidazole that is utilized in the manufacture of such classes of items as pharmaceuticals, pesticides, ion-exchange resins, dye intermediates, textile auxiliaries, photographic chemicals, and corrosion inhibitors. It is also used as a catalyst for manufacturing polyurethanes and a curing agent for epoxy resins. 1-Methylimidazole has been utilized in the synthesis of inorganic complexes, ionic liquids, and catalytic deprotonation reagents.

The use of 1-methylimidazole in the preparation of GDP-hexanolamine for the purification of fucosyltransferases has been reported.

Membranes based on the polybenzimidazole (PBI) doped with phosphoric acid have already been described as an attractive candidate for high temperature(150-200 degree C) PEM fuel cells. These membranes exhibit high conductivities at relatively low humidity as compared with low temperature polymer electrolyte membranes. In addition, they have excellent mechanical properties and provide good separation between the fuel and oxidant streams, thus there are only small amounts of gas crossover. The proton conduction mechanism in the solid solution of the phosphoric acid (PA) doped polymer may be attributed to conduction through a chain of acid molecules. This model has been used to describe theconduction in concentrated liquid phosphoric acid.

In recent work, the authors present the conductivity results of liquid sulfuric acid with additives of imidazole and pyrazole. Their results indicate that concentrations of 515%(m) of imidazole in H2SO4 improve the observed conductivities by a factor of 7 to 10. Similar behavior was also identified by them for the same solution after adding 10% (m) water. The authors attribute the high conductivity to water like behavior of these molecules as well as to increase in the number of proton defects in doped acids solutions. These results have motivated us to investigate the conductivity of concentrated phosphoric acid with similar additives. The influence of imidazole(IM) and 1-methylimidazole(CAS:616-47-7) on the conductivity of liquid H3PO4 99% (wt) solutions and on PBI/PA membranes was studied over a broad temperature range and at several humidification levels. Research on oxygen reduction at platinum electrodes in a PEM fuel cell with PBI/H3PO4/Im membranes and in liquid solution of concentrated phosphoric acid containing imidazolium salts is also under study. The results of this work will be presented as a separate communication.

An investigation of the kinetics of copper uptake by apoazurin has used 1-methylimidazole as a buffer over the pH range 7-9. 1-Methylimidazole has been utilized as a buffer in a study of nucleotide binding to the sarcoplasmic reticulum Ca2+-ATPase. An investigation of hydrogen bonding of substrates to a heme-pocket water in the Bradyrhizobium japonicum FixL heme domain that uses 1-methylimidazole has been published.

Uriahyang is the freelance writer for e-commerce website in the chemistry. Guidechem.com is just a place for you to look for some chemicals! Our guidechem provide the most convenient conditions for the international buyers and let these leads benefit all the business people.