聚苯并咪唑/两性离子修饰氧化石墨烯复合质子交换膜的制备与表征

Preparation and Characterization of Composite Proton Exchange Membrane of Polybenzimidazole/Zwitterion-Coated Graphene Oxide

合成了两性离子修饰的氧化石墨烯（ZC-GO）,以聚苯并咪唑（PBI）为基体,ZC-GO为质子载体制备了PBI/ZC-GO复合质子交换膜,由于对氧化石墨烯（GO）表面进行了修饰,使得改性石墨烯形成了疏水-亲水结构.测试了复合膜的FT-IR、SEM、吸水率、离子交换容量和质子电导率等性能.结果表明：该质子交换膜具有良好的热稳定性和较高的电导率,在100％相对湿度,80℃时,复合膜（ZC-GO含量为10％）的电导率达到2.2×10-2 S/cm.与纯的PBI膜相比,PBI/ZC-GO复合膜的吸水能力显著提高;其甲醇渗透率为（3.16～7.23）×10-7 cm2/s,虽然与纯PBI膜相比稍有增加,但仍大大低于Nafion膜的甲醇渗透率,有望应用于直接甲醇燃料电池中.

The zwitterion-coated graphene oxide （ZC-GO） was synthesized and used as filler for the preparation of PBI-based composite membranes for direct methanol fuel cells.Hydrophilic-hydrophobic structure formed on the surface of ZC-GO by the chemical modification of ZC-GO.The morphology,composition and structural features of the composite membranes were investigated by scanning electron microscopy （SEM） and fourier transform infrared （FT-IR） spectroscopy.The water uptake,ionic exchange capacity and proton conductivity of the composite membranes increased with the ZC-GO content.The results show that the composite membranes have good thermal stability and high conductivity,and the membrane with 10％ of ZC-GO shows the conductivity of 2.2× 10-2S/cm at 80℃ and 100％ humidity.The methanol permeability of the composite membranes was （3.16～7.23） ×10-7cm2/s,which is a little higher than that of pure PBI membrane,but it＇s still much lower than that of Nation membrane.The properties of the composite membranes indicate their promising prospects in direct methanol fuel cells.