Fabrication and Characteristics of Poly(benzimidazole/fluoro/ether/siloxane/amide)/Sulfonated Polystyrene/Silica Nanoparticle-Based Proton Exchange Membranes Doped With Phosphoric Acid

Novel poly(benzimidazole/fluoro/ether/siloxane/amide) (PBFESA) was developed for the formation of hybrid proton exchange membrane. Afterward, phosphoric acid doped PBFESA/PS-S/SiNPs was prepared with PBFESA, sulfonated polystyrene (PS-S), and 0.1-2wt% silica nanoparticles (SiNPs). Tensile strength of acid doped PBFESA/PS-S/SiNPs nanocomposites increased from 63.9 to 68.1MPa with increasing SiNPs loading. They had higher ion exchange capacity (IEC) of 2.3-3.3mmol/g and proton conductivity of 1.9-2.7S/cm at 80 degrees C (higher than perfluorinated Nafion 117 membrane 1.1x10(-1)S/cm). A H-2/O-2 fuel cell using PBFESA/PS-S/SiNPs 2 (IEC 3.3mmol/g) showed better performance than Nafion 117 at 40 degrees C (30% RH). [GRAPHICS]