High-Performance of PEI/Nafion®/ox-MWCNT Composite Membranes Based on Semi-Interpenetrating Polymer Networks for PEMFCs

Polymer electrolyte membrane fuel cells (PEMFCs) are an up-and-coming technology for green and efficient power generation and offer a clean alternative to current technologies that use hydrocarbon fuel sources. In this paper, a reinforcing membrane was fabricated by Polyethylenimine polymer. Oxidized multiwalled carbon nanotube was dispersed into the PEI/Nafion membranes to achieve additional strength. The membranes were acidified via absorption of phosphoric acid from aqueous solution to make semi-interpenetrating polymer network (s-IPNs) which increases the proton conductivity by producing proton channel in the membrane. The PEI/Nafion/ox-MWCNT composite membranes show excellent phosphoric acid retention and high humidity, which impart a high ion exchange capacity (IEC) as well as improved proton conductivity. The surface morphologies and cross-sections of the resulting H3PO4 treated PEI/Nafion/ox-MWCNT composite membranes were observed using optical microscopy and scanning electron microscopy (SEM). The improvements in the thermal properties of the prepared PEI/Nafion/ox-MWCNT composite membranes were determined using thermogravimetric analysis (TGA). These performance results combined with the low inexpensive synthetic approach substantiate the potential for the new membrane to be used in PEMFCs.