Multi-walled carbon nanotubes (MWCNTs) are regarded as ideal fillers for Nafion (R) polymer electrolyte membranes (PEMs) for fuel cell applications. The highly aggregated properties of MWCNTs can be overcome by the successful cross-linking with polyvinyl alcohol (PVA) into the MWCNT5/Nafion (R) membrane. In this study, a series of nanocomposite membranes were fabricated with the PVA-influenced functionalized MWCNTs reinforced into the Nafion (R) polymer matrix by a solution casting method. Several different PVA contents were blended to f-MWCNT5/Nafion (R) nanocomposite membranes followed by successful cross-linking by annealing. The surface morphologies and the inner structures of the resulting PVAMWCNTs/Nafion (R) nanocomposite membranes were then observed by optical microscopy and scanning electron microscopy (SEM) to investigate the dispersion of MWCNTs into the PVA/Nafion (R) composite membranes. After that, the nanocomposite membranes were characterized by thermo-gravimetric analysis (TGA) to observe the thermal enhancement caused by effective cross-linking between the f-MWCNTs with the composite polymer matrixes. Improved water uptake with reduced methanol uptake revealed the successful fabrication of PVA-blended f-MWCNTs/Nafion (R) membranes. In addition, the ion exchange capacity (IEC) was evaluated for PEM fuel cell (PEMFC) applications.
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