Guilizzoni M., Gallo Stampino P., Cristiani C., Dotelli G., Latorrata S., 2013, Formulation and Properties of Different Microporous Layers with Carboxymethylcellulose (CMC) Composition for PEM-FC, Chemical Engineering Transactions, 32, 1657-1662.
Inks formulation to deposit microporous layers (MPL) for polymer electrolyte membrane fuel cells (PEM- FCs) application were studied. The effect of the addition of carboxymethylcellulose (CMC) on slurry rheological behaviour and on final morphological, electrical and wettability properties of the so-obtained MPLs were assessed. For this purpose different formulation, namely with and without CMC, were compared. The presence of CMC resulted in a general increase of slurry viscosity and stability. Wettability analyses for surface characterization were performed by means of contact angle measurements applying the sessile drops technique. Static contact angles and contact angle hysteresis were evaluated at ambient temperature, at 60 °C and at 80 °C. Drop evaporation at the three temperatures was also evaluated. The presence of residual amounts of CMC, not fully decomposed upon MPL thermal treatment, affected negatively the final MPL characteristics in terms of hydrophobicity. Fuel cell assemblies using MPLs with and without CMC showed different electrochemical performances in terms of I-V curves and impedance spectra. CMC-containing MPLs showed electrochemical performances that were influenced by the CMC content: more CMC induced a decrease in power density. However, CMC-based MPLs exhibited lower ohmic resistances.
