Degradation of radiation grafted hydroxide anion exchange membrane immersed in neutral pH: removal of vinylbenzyl trimethylammonium hydroxide due to oxidation

Abstract

Degradation tests in deionised water of radiation grafted anion exchange membranes for fuel cell/electrolyser operation showed loss of vinylbenzyl trimethylammonium groups.

Soluble Polystyrene‐b‐poly (ethylene/butylene)‐b‐polystyrene Based Ionomer for Anion Exchange Membrane Fuel Cells Operating at 70 °C

“…The through‐plane ionic conductivity of each of the functionalized membranes was measured following the same procedure previously reported using the following formula: …”

“…The IECs were computed using the amount of OH − ions neutralized, expressed in mmole, divided by the dry weight of the membranes, in grams. Degree of grafting (S3) of the membrane based on initial weight (DOG) is 67.5% and IEC (S4) is 2.3 mmol g −1 with final hydrated membrane thickness of 75 μm , . The ion exchange capacity of the SEBS ionomer was 1.91 mmol g −1 and the degree of chloromethylation (S5) was 49% .…”

“…Another important aspect of membrane (and ionomer) is fast water permeability to allow water transfer from the anode to the cathode. Chemical stability of AEM materials at elevated temperatures and low humidity. We have shown that trimethylamine based AEM membrane had stable OH − conductivity of 0.11 S cm −1 at 80 °C and 100% RH under N 2 for 6 month , but conductivity decreased rapidly under oxygen atmosphere due to radicals attacks , on benzylic ternary carbon , . Lack of chemically stable high performance AEM ionomer. Ionomer must have high ion conductivity and stability in the alkaline environment , , , .…”

“…Chemical stability of AEM materials at elevated temperatures and low humidity. We have shown that trimethylamine based AEM membrane had stable OH − conductivity of 0.11 S cm −1 at 80 °C and 100% RH under N 2 for 6 month , but conductivity decreased rapidly under oxygen atmosphere due to radicals attacks , on benzylic ternary carbon , .…”

Detection of Reactive Oxygen Species in Anion Exchange Membrane Fuel Cells using In Situ Fluorescence Spectroscopy

“…[4][5][6] Similarly,m etallic platinum can also catalyze the formation of free radicalsa sd etailed elsewhere. [12] Therefore, it is essential to develop am ethodf or detecting/quantifying O 2 C À formation in operating AEMFCs. [9][10][11] O 2 C À has al ong half-life in the highly alkaline environment prevalent in the AEM and can cause significant oxidative damage to the membrane.…”