In this paper the investigation on the rheological, morphological and electrical behaviour of the addition of carboxymethylcellulose (CMC) in two different inks (used to coat a Micro Porous Layer or MPL) was studied. For the sake of comparison two inks with and without the CMC and the same amount of PTFE (12 wt%) were prepared. The presence of CMC drives to a different rheological curve with respect to that obtained for standard composition ink and, in particular, to a general increase in viscosity and to a more shear- thinning behaviour. Two Gas Diffusion Layers (GDLs) were obtained by coating via doctor blade technique the MPLs onto the carbon cloth. Hydrophobicity and morphology of the MPLs coatings were assessed by contact angle measurements and SEM analyses. The two GDLs so obtained, were also tested in a single Polymer Electrolyte Membrane Fuel Cell and its performances evaluated. The membrane electrode assembly was made of Nafion~R 212 with Pt load 0.3/0.6 mg cm~(-2) (anode/cathode). The cell testing was run at 60°C and 80°C, fed with 80%RH hydrogen and air at two different RHs (60 and 100%). PEMFC performances in the various configurations were assessed by polarization and power curves.
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