Nano Composite Membranes of Sulfonated Poly(ether sulfone)s Containing Tetraphenylethylene moiety and SiO2 for PEMFC

Conjugated cis/trans isomer-based polymer membranes were prepared with 25 mol% of bis (4-hydroxyphenyl)-1,2-diphenylethylene (BHDPE). BHDPE has a conjugated nonplanar conformation structure containing the peripheral four aromatic rings which facilitate the formation of π-π interactions. A series of sulfonated poly (ethersulfone) s (SPBHDPE) was synthesized with concentrated sulfuric acid. The sulfonation took place selectively on the BHDPE unit, and simultaneously on the side-chain and main-chain phenyl groups. The SPBHDPEs consisted of a 4:6 ratio of cis and trans form mixtures. Composite membranes were prepared with copolymers and SiO2 nanoparticles (20 nm, 4~10%wt). The composite membranes were cast from DMSO. A series of composite membranes structures and characteristic were evaluated by the 1H-NMR spectroscopy, and thermal stabilities. The membranes were performed by ion exchange capacity (IEC), water uptake and proton conductivity.