Fluid distribution in artificially manufactured porous mixed-wetting materials as a model for gas diffusion electrodes

• Implementation of a 2D+1D simulation captures real wetting phenomena • Our micromodel with different surfaces accurately depicts mixed wettability in a controlled microenvironment • Comparison between experimental and numeric data reveals the impact of layer- or cornerflow • Our SPH simulation was validated analytically and experimentally Mixed wettability of porous media plays a crucial role in processes involving enhanced oil recovery, catalysis, membrane filtration and porous electrodes. To comprehend, optimize and implement these processes, a comprehensive understanding of the influence of spatial surface energy distribution on wettability is pivotal. Direct measurement of fluid distributions in porous media is challenging. Therefore, direct numerical simulation (DNS) is often employed. We propose a microfluidic device incorporating hydrophilic and hydrophobic surfaces with wetting properties comparable to silver-based gas diffusion electrodes. Displacement experiments were conducted to validate simulation predictions. Experimental findings were compared to Smoothed Particle Hydrodynamics (SPH) simulations. We observed the following key details: (a) Our micromodel accurately depicts mixed wettability. (b) Implementation of a 2D+1D simulation captures real wetting phenomena. (c) Comparisons between experiment and simulation reveal the impact of cornerflow. This coupled approach facilitates planned design of porous media and fosters the understanding of transport in microporous networks.