From polymer chemistry to membrane elaboration

Anion exchange membranes based on semi-interpenetrating polymer network of quaternized chitosan and polystyrene

“…The well-known Hoffman degradation may cause the elimination of quaternary ammonium and thus low conductivity [48]. The substantive drop on the conductivity around 96 h for semi-IPN-0 is mainly attributed to the Hoffman degradation.…”

Formation and evaluation of interpenetrating networks of anion exchange membranes based on quaternized chitosan and copolymer poly(acrylamide)/polystyrene

“…The membrane degradation due to the nucleophilic attack of OH − is of a great concern for the quaternary ammonium polymers. The well-known Hoffman degradation may cause the elimination of quaternary ammonium and thus low conductivity [67]. The obvious drop in the conductivity at the time of around 120 h for QCS 100 -(PAM/PS) 0 is mainly attributed to the Hoffman degradation.…”

New hyperbranched polymers for membranes of high‐temperature polymer electrolyte membrane fuel cells: Determination of the crystal structure and free‐volume size

“…For example, it cannot be operated under dry conditions, and at high temperatures (>100°C), there is an issue of water management under humid conditions; it also has inadequate barrier properties. The other challenges with Nafion membranes are its critical system design and operation with respect to water management, a low tolerance for fuel impurities, and the poisoning of the electrode by carbon monoxide 1–5…”

“…The other challenges with Nafion membranes are its critical system design and operation with respect to water management, a low tolerance for fuel impurities, and the poisoning of the electrode by carbon monoxide. [1][2][3][4][5] To resolve the aforementioned problems, recent research in PEMFCs has focused mainly on the development of high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) membranes that operate well above 100 C. [6][7][8] As reported previously, the phosphoric acid doped polybenzimidazole (PBI) membrane is the most preferred basic polymer membrane for HT-PEMFCs and can be operated at 100-220 C without humidity. 7,8 The operation of a fuel cell at higher temperatures ensures a higher efficiency, high power density, reduced sensitivity to carbon monoxide poisoning of the electrode, and better controllability (because of the absence of water management issues in the membrane).…”