We propose for the first time an aromatic polyazomethines applied in polymer electrolyte membrane fuel cells (PEMFC) as tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid copolymer (PFSA) membrane modifiers. Two types of polyazomethines were selected to impregnate pristine PFSA membranes, the one with bibenzimidazole groups (25Bo-BABPI) and the second with thiophene rings (2252Th-DMB). In addition, these composite membranes were doped using imidazole (Im) to increase the proton conductivity. The success of impregnation process of all modified membranes has been confirmed based on FTIR spectroscopy. Obtained PFSA composite membranes were thermally stable (TGA, DTG results) and revealed lower dependency on water as an advantage, according to water sorption analysis performed. The particular membranes were activated in boiling deionized water and then in 3.75 % H2O2, and finally in boiling 0.2M H2SO4. Moreover, both polyazomethines were oxidized with FeCl3 to check their chemical oxidation abilities. Single PEMFCs assembled using polyazomethine composite membranes are characterized by improved performance as well as double increase of maximum power density, higher proton conductivity and larger electrochemical surface area of catalyst in comparison to reference samples. The maximum power density of 231 mW/cm2 at the current density of 637 mA/cm2 was detected for PFSA-25Bo-BABPI membrane. In accordance with experiments carried out, polyazomethines have positive influence on PEMFC overall electrochemical properties. All membranes were tested by atomic force microscopy (AFM) and scanning electron microscopy (SEM) with EDX to analyzed their morphology properties.

中文翻译：

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聚偶氮甲碱及其与Nafion和Nafion-咪唑膜的酸碱相互作用，可用于高效燃料电池

我们首次提出芳族聚偶氮亚胺作为四氟乙烯-全氟-3,6-二氧杂-4-甲基-7-辛烯-磺酸共聚物（PFSA）膜改性剂应用于聚合物电解质膜燃料电池（PEMFC）。选择了两种类型的聚偶氮甲碱来浸渍原始的PFSA膜，一种具有联苯并咪唑基团（25Bo-BABPI），另一种具有噻吩环（2252Th-DMB）。另外，使用咪唑（Im）掺杂这些复合膜以增加质子传导性。基于FTIR光谱法已经证实了所有改性膜的浸渍过程的成功。根据进行的吸水分析，获得的PFSA复合膜是热稳定的（TGA，DTG结果），并且显示出对水的依赖性较低，这是一个优势。特定的膜在沸腾的去离子水中活化，然后在3.75％的H2O2中活化，最后在沸腾的0.2M H2SO4中活化。此外，两种聚偶氮甲亚胺均被FeCl3氧化，以检查其化学氧化能力。与参考样品相比，使用聚偶氮甲碱复合膜组装的单个PEMFC具有以下特点：性能提高，最大功率密度增加一倍，质子传导率更高，催化剂的电化学表面积更大。对于PFSA-25Bo-BABPI膜，在637 mA / cm2的电流密度下检测到231 mW / cm2的最大功率密度。根据进行的实验，聚偶氮甲碱对PEMFC的整体电化学性能具有积极影响。