• Membrane Journal
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• v.27 no.1
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• pp.53-59
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• 2017

In this study, the composite membranes prepared by sulfonated graphene oxide (sGO) and Nafion were developed as proton exchange membranes (PEMs) for polymer electrolyte membrane fuel cells (PEMFCs). The sGO/Nafion composite membranes were prepared by mixing Nafion solution with the sGO dispersed in a binary solvent system to improve dispersity of sGO. The composite membranes were investigated in terms of ionic conductivity, ion exchange capacity (IEC), FT-IR, TGA and SEM, etc. As a result, the binary solvent system, i.e., ortho-dichlorobenzene (ODB) and N,N-dimethylacetamide (DMAc), were used to obtain high dispersion of sGO particles in Nafion solution, and the ionic conductivity of the sGO/Nafion composite membrane showed $0.06Scm^{-1}$ similar to other research results at lower water uptake, 11 wt%.

• Membrane Journal
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• v.33 no.6
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• pp.416-426
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• 2023

In this study, hindered amine-grafted graphene oxide (HA-GO) with antioxidant properties was prepared and incorporated into Nafion-based composite membranes as an effective filler material for polymer electrolyte membrane fuel cell applications. HA-GO was synthesized via a ring-opening reaction between amine groups in 4-amino-2, 2, 6, 6-tetramethyl piperidine and epoxy groups on the surface of GO. Nafion-based composite membranes containing different weight contents of HA-GO were fabricated to compare the polymer electrolyte membrane properties with those of the pure Nafion membrane. The composite membranes with HA-GO were found to have better mechanical properties, chemical stability, and proton conductivity than the pure Nafion membrane. In particular, the conductivity retention behavior confirmed by the decrease in proton conductivity after Fenton's test of the composite membranes was better than that of the pure Nafion membrane due to the incorporation of HA-GO with effective antioxidant properties.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.127-131
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• 2016

Polymer electrolyte membrane for unitized regenerative fuel cells requires high proton conductivity, high dimensional stability, low permeability, and low cost. However, DuPont's Nafion which is a commercial polymer electrolyte membrane has high permeability, high cost, and decreasing proton conductivity and dimensional stability over $80^{\circ}C$. To address these problems, sulfonated poly ether ether ketone (sPEEK) which is a low cost hydrocarbon polymer is selected as matrix polymer for the preparation of polymer electrolyte membrane. In addition, composite membrane with improved proton conductivity and dimensional stability is prepared by introducing sulfonated graphene oxide (sGO). The fundamental properties of polymer electrolyte membranes are analyzed by investigating membrane's water content, dimensional stability, proton conductivity, and morphology. The cell test is conducted to consider the possibility of application of sPEEK/sGO composite membrane for an unitized regenerative fuel cell.