scholarly journals Ameliorated Performance of Sulfonated Poly(Arylene Ether Sulfone) Block Copolymers with Increased Hydrophilic Oligomer Ratio in Proton-Exchange Membrane Fuel Cells Operating at 80% Relative Humidity

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1871 ◽  
Author(s):  
Ae Kim ◽  
Mohanraj Vinothkannan ◽  
Kyu Lee ◽  
Ji Chu ◽  
Sumg Ryu ◽  
...  

We designed and synthesized a series of sulfonated poly(arylene ether sulfone) (SPES) with different hydrophilic or hydrophobic oligomer ratios using poly-condensation strategy. Afterward, we fabricated the corresponding membranes via a solution-casting approach. We verified the SPES membrane chemical structure using nuclear magnetic resonance (1H NMR) and confirmed the resulting oligomer ratio. Field-emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM) results revealed that we effectively attained phase separation of the SPES membrane along with an increased hydrophilic oligomer ratio. Thermal stability, glass transition temperature (Tg) and membrane elongation increased with the ratio of hydrophilic oligomers. SPES membranes with higher hydrophilic oligomer ratios exhibited superior water uptake, ion-exchange capacity, contact angle and water sorption, while retaining reasonable swelling degree. The proton conductivity results showed that SPES containing higher amounts of hydrophilic oligomers provided a 74.7 mS cm−1 proton conductivity at 90 °C, which is better than other SPES membranes, but slightly lower than that of Nafion-117 membrane. When integrating SPES membranes with proton-exchange membrane fuel cells (PEMFCs) at 60 °C and 80% relative humidity (RH), the PEMFC power density exhibited a similar increment-pattern like proton conductivity pattern.

2013 ◽  
Vol 51 ◽  
pp. 22-28 ◽  
Author(s):  
Jeong Hwan Chun ◽  
Sang Gon Kim ◽  
Ji Young Lee ◽  
Dong Hun Hyeon ◽  
Byung-Hee Chun ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Chiang Huang ◽  
Ruei-Hong Tai ◽  
Hsu-Feng Lee ◽  
Po-Hsun Wang ◽  
Ram Gopal ◽  
...  

A series of sterically hindered, sulfonated, poly(arylene ether) polymers were synthesized by nucleophilic polycondensation reaction using 4,4′′′′-difluoro-3,3′′′′-bistrifluoromethyl-2′′,3′′,5′′,6′′-tetraphenyl-[1,1′;4′,1′′;4′′,1′′′;4′′′,1′′′′]-pentaphenyl and 4,4′-biphenol and were prepared through postpolymerization sulfonation. The chemical structures were confirmed by1H NMR. Subsequent to sulfonation, solvent-casting membranes were provided ion exchange capacity (IEC) values ranging from 0.39 to 2.90 mmol/g. Proton conductivities of membranes ranged from 143 to 228 mS/cm at 80°C under fully humidified conditions which were higher than that of Nafion 117. The membrane also exhibited considerably dimension stability, oxidative stability, and hydrolytic stability. The microphase structure was investigated by transmission electron microscopy (TEM) and the ionic aggregation of sulfonic acid groups exhibited spherical ionic clusters with well-developed phase separated morphology. The results indicated that the membranes are promising candidates for application as proton exchange membranes. This investigation demonstrates introducing multiphenylated moieties to create a high free volume polymer that provides dimensionally stable and high proton conductivity membranes.


2014 ◽  
Vol 577 ◽  
pp. 53-57
Author(s):  
Hang Wei ◽  
Guang Li

Sulfonated poly (arylene ether sulfone) s (SPAESs) exhibit good proton conductivity, thermal and mechanical properties, could act as candidates of proton exchange membranes for fuel cells. At the same time, the poor oxidative stability and excessive swelling ratio of SPAESs bring limitations for its further use. In this article, PAN was employed to mix with SPAES, and then SPAES/PAN blend membranes were prepared from the blend solution by casting. The water uptake, dimensional and oxidative stability, proton conductivity were measured with respect to the addition content of PAN, the phase morphology of the resultant SPAES/PAN were also observed by SEM. The results explained that the corporation of PAN into SPAES could reduce the water uptake and improve the oxidative stability of the obtained membranes compared with the pristine SPAES membrane. That the PAN phase distributed as separated domains in SPAES matrix was found, the interaction between SPAES and PAN may be present, which is responsible for the improvement of dimensional and oxidative stability. Although the proton conductivity of the blend membranes became reduced with increase of PAN content in the SPAES/PAN blend, the conductivity of 0.0265S/cm at 30°C could still be reached, satisfying the requirement for proton exchange membrane Fuel Cell


RSC Advances ◽  
2017 ◽  
Vol 7 (45) ◽  
pp. 28358-28365 ◽  
Author(s):  
Sun Hwa Lee ◽  
Won Jun Lee ◽  
Tae Kyoung Kim ◽  
Mustafa K. Bayazit ◽  
Sang Ouk Kim ◽  
...  

UV-crosslinked sulfonated poly(arylene sulfone)/clay nanocomposites are fabricated by incorporating UV-crosslinkable monomers, bridge molecules, and clay nanofillers for high performance proton exchange membrane fuel cells.


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