InterPore2026

Modeling Drying of a Colloidal Dispersion in a Fibrous Porous Medium Using Full Morphology Approach

21 May 2026, 15:05

15m

Oral Presentation (MS17) Electrochemical Processes in Porous Media MS17

Speaker

Pierluigi Arnelli (Univ. Grenoble Alpes, CEA, Liten, DEHT)

Description

Proton Exchange Membrane Fuel Cell is considered as an attractive pollutant-free alternative to thermal engines, especially for Heavy Duty applications. In this context, the study focuses on one major fuel cell components: the gas diffusion layer (GDL). The GDL is a thin porous medium, made of graphitized carbon fibers. To increase performance, a treatment is performed to render the GDL hydrophobic. It consists in dipping it in a polytetrafluoroethylene (PTFE) colloidal dispersion. Then, the medium is dried and sintered [1]. As it can be seen in the image (Fig.1), the PTFE after the treatment does not coat evenly all the fibers, and preferentially accumulates where the fibers are close to each other. As the PTFE distribution impacts the GDL properties [2], it is of interest to simulate the PTFE treatment step to predict its 3D distribution and the corresponding GDL single and two-phase transport properties. This will contribute to better predict the cell performance and improve treatment parameters to increase performance.
To this end, Daino et al. simulated the PTFE addition on 3D microstructures of GDL by using morphological closure [3], which is an image treatment that fills holes and small crevices in the image. Inoue et al. solved two-phase transport equations for PTFE particles and for dispersion saturation given by a continuous model [4].
Our work is based on a full morphology approach. Developed to simulate two-phase transport in a porous medium in the quasi-static limit, the full morphology approach is also image-based and consists in determining which parts of the media are accessible to a certain phase, by combining Laplace law and geometrical considerations. To do this type of simulation, Schulz et al. used morphological operations on images called dilation and erosion [5], while Sabharwal et al. developed a method based on the evaluation of pore size distribution [6].
To predict the PTFE distribution after drying, monitoring of PTFE concentration is performed in conjunction with the full morphology approach. In other words, drying simulation is performed via full morphology, while also computing the increase in PTFE concentration resulting from the solvent evaporation, until there is no solvent left. The computations are performed on 2D and on 3D GDL images obtained by x-ray tomography. Results of both full morphology algorithms mentioned in the previous paragraph are compared. The PTFE structures obtained are then compared to SEM images of the treated GDL. Also, through-plane distribution of PTFE in the material is compared to the experimental through-plane distribution obtained from EDX analysis.

Acknowledgement: This research is part of the project “DECODE" which has received funding from the European Union’s Horizon Europe research and innovation program under grant agreement N° 101135537. More information on the project can be found at www.decode-energy.eu.