Fractal analysis of gas diffusion layer in PEM Fuel Cells

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer (GDL) in Proton Exchange Membrane Fuel Cell (PEMFC). The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene (PTFE) treated carbon paper shows a significantly high fractal dimension value than pure sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modifications in the processing of materiah.