Composites membranes based on Nafion and PAMAM dendrimers for PEMFC applications

• PAMAM dendrimers are incorporated into Nafion matrix to prepare membranes.
• The membranes are tested in a DMFC and compared with recast bare Nafion.
• Tests in 2 M methanol/air revealed higher performance of the dendrimer membrane.
• PAMAM polymers turned out an effective option to reduce the methanol crossover.

The aim of this work consists in to incorporate organic compounds as PAMAM (Poly-amidoamine) dendrimers into the polymeric Nafion matrix to prepare composite membranes as a possible alternative to reduce methanol crossover effect. Composite Nafion membranes were prepared using a 3 wt% of Generation-4 hydroxyl-terminated PAMAM (G4OH) dendrimers containing 64-terminal OH-functional groups. The influence of PAMAM-(G4OH) dendrimer on chemical–physical properties of the composite membrane was highlighted resulting in a reduction of the methanol permeability (1.05 × 10−6 cm2 s−1) if compared to a recast bare Nafion membrane (8.19 × 10−6 cm2 s−1), used as a reference. Good proton conductivity was also observed for PAMAM-(G4OH) composite membrane. The polarization curves carried out at 100 °C in the presence of 2 M methanol have revealed the higher performance of the PAMAM-(G4OH) membrane when compared to a recast Nafion membrane.