Preparation And Performance Of Organic-inorganic Composite Proton Exchange Membrane Based On Poly (Phenylene Oxide)

Fuel cell power system has significant effects to solve energy shortage and environmentalpollution, which translate directly chemical energy into electrical energy. Proton exchangemembrane fuel cell (PEMFC), one of fuel cells, have some advantages, such as high efficiency,environment-friendly, quick start at room temperature, which has caught great interests ofscientists in recent years.Nafion, produced by DuPont, is used widely in proton exchange membrane fuel cell withhigh proton conductivity and chemical stability. But it is still limited in commercial applicationbecause of high price ($800/m2), low operate temperature (<100℃) and environmental pollutionin production process. To solve these problems, sulfonated polyphenylene oxide (SPPO) waschosen as matrix. Graphene oxide (GO), halloysite nanotubular (HNTs) and montmorillonite(MMT) were added to the SPPO matrix respectively and fabricated organic-inorganic compositeproton exchange membranes. Performances of composite membranes were reasearched and themechanism of proton transfer was explored.Graphene oxide was prepared by chemical oxidation and modified withmercaptopropyltrimethoxysilane. Sulfonic acid group was introduced into the graphene oxidesheets. SPPO/F-GO composite films were fabricated and performances of the compositemembrane were investigated. The results showed that water uptake and swelling degree swellingdegree were decreased; mechanical properties were enhanced due to the addition of grapheneoxide. Graphene oxide can significantly improve proton conductivity of the compositemembrane. The proton conductivity of SPPO/1.5%F-GO was higher76%than that of pureSPPO membrane.Sulfontaed GO (sGO) was prepared by modification with1,3-Propanesultone andcharacterized by FTIR and XPS. It showed that1,3-Propanesultone was successfully grafted onthe GO.SPPO/sGO composite membranes were fabricated and performances of the compositemembrane were investigated. The results showed sGO can obviously promote the proton transfer.At90℃,100RH,the proton conducticity of1.5%sGO membranes was2.7×10-2S cm-1. It washigher164%than that of pure SPPO membrane. sGO can improve the antioxidanted time. Theantioxidanted time of SPPO/5%sGO was2h, which was longer that of pure SPPO membrane(45min). Halloysite was modified by mercaptopropyltrimethoxysilane. SPPO/mHNTs compositefilms were fabricated and performances of the composite membrane were investigated. Theresults showed that water uptake and swelling degree swelling degree were also decreased, andmechanical properties and proton conductivity were enhanced due to HNTs. Proton conductivityof the composite membraneof SPPO/3%mHNTs was higher110.5%than that of pure SPPOmembrane.Montmorillonite was modified by3-aminopropyl triethoxy silane. SPPO/APS-MMTcomposite films were fabricated and the performances of the composite membrane wereinvestigated. The results showed that water uptake and swelling degree swelling degree weredecreased; mechanical properties were enhanced due to MMT. But the layered MMT can hinderthe proton transfer, which result in the decrease of proton conductivity of the compositemembrane with the addition of MMT.