Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science & Technology , 200 Xiaolingwei, Nanjing 210094, Jiangsu Province, China.
Department of Organic and Polymeric Materials, Tokyo Institute of Technology , 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552, Japan.
ACS Appl Mater Interfaces. 2017 Sep 27;9(38):33049-33058. doi: 10.1021/acsami.7b07777. Epub 2017 Sep 13.
To improve proton conduction properties of conventional sulfonated poly(ether ether ketone) (SPEEK), poly(2,5-benzimidazole)-grafted graphene oxide (ABPBI-GO) was prepared to fabricate nanocomposite membranes, which then were further doped with phosphoric acid (PA). The ABPBI-GO was synthesized through the reaction of 3,4-diaminobenzoic acid with the carboxyl acid groups present on the GO surface. The simultaneous incorporation of ABPBI-GO and PA into SPEEK did not only improve the physicochemical performance of the membranes in terms of thermal stability, water uptake, dimensional stability, proton conductivity, and methanol permeation resistance but also relieve PA leaching from the membranes though acid-base interactions. The resulting composite membranes exhibited enhanced proton conductivities in extended humidity ranges thanks to the hygroscopic character of PA and the increased water uptake. Moreover, the unique self-ionization, self-dehydration, and nonvolatile properties of PA improved the high-temperature proton conductivities (σ) of PA-doped membranes. The PA-doped SPEEK/ABPBI-GO-3.0 delivered a σ of 7.5 mS cm at 140 °C/0% RH. This value was fourfold higher than that of pristine SPEEK membranes. The PA-doped SPEEK/ABPBI-GO-3.0 based fuel cell membranes delivered power densities of 831.06 and 72.25 mW cm at 80 °C/95% RH and 120 °C/0% RH, respectively. By contrast, the PA-doped SPEEK membrane generated only 655.63 and 44.58 mW cm under the same testing conditions.
为了提高传统磺化聚醚醚酮 (SPEEK) 的质子传导性能，制备了接枝聚（2,5-苯并咪唑）-氧化石墨烯 (ABPBI-GO) 纳米复合材料膜，然后进一步用磷酸 (PA) 掺杂。ABPBI-GO 通过 3,4-二氨基苯甲酸与 GO 表面存在的羧酸基团之间的反应合成。将 ABPBI-GO 和 PA 同时掺入 SPEEK 中，不仅提高了膜的物理化学性能，如热稳定性、吸水率、尺寸稳定性、质子电导率和甲醇渗透率，而且通过酸碱相互作用缓解了 PA 从膜中浸出。由于 PA 的吸湿性和吸水率的增加，得到的复合膜在扩展的湿度范围内表现出增强的质子电导率。此外，PA 的独特的自电离、自脱水和不挥发特性提高了 PA 掺杂膜的高温质子电导率 (σ)。在 140°C/0%RH 下，PA 掺杂的 SPEEK/ABPBI-GO-3.0 的 σ 达到 7.5 mS cm，是原始 SPEEK 膜的四倍。基于 PA 掺杂的 SPEEK/ABPBI-GO-3.0 的燃料电池膜在 80°C/95%RH 和 120°C/0%RH 下分别提供 831.06 和 72.25 mW cm 的功率密度，而在相同测试条件下，PA 掺杂的 SPEEK 膜仅产生 655.63 和 44.58 mW cm。
