This paper introduces a newly developed methodology for the pore-scale simulation of flow, diffusion and reaction in the coated catalytic filter. 3D morphology of the porous filter wall including the actual distribution of catalytic material is reconstructed from X-ray tomography (XRT) images and further validated with the mercury intrusion porosimetry (MIP). The reconstructed medium is then transformed into simulation mesh for OpenFOAM. Flow through free pores in the substrate as well as through the coated zones is simulated by porousSim-pleFoam solver, while an in-house developed solver is used for component diffusion and reactions. Three cordierite filter samples with different distribution of alumina-based coating ranging from in-wall to on-wall are examined. Veloc-

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Catalytic monolith filters with a honeycomb structure represent a key component of modern automotive exhaust gas aftertreatment systems. In this paper, we present and validate a multiscale modeling methodology for the prediction of filter pressure loss depending on the monolith channel geometry as well as the microscopic structure of the wall including catalytic coating. The approach is based on the combination of a 3D pore-scale model of flow through the wall reconstructed from X-ray tomography and a 1D+1D model of the filter channels. Several cordierite and SiC filter samples with varying substrate pore sizes and catalyst distributions are examined. A series of experiments are performed at different gas flow rates and filter lengths in order to validate the model predictions and to distinguish individual pressure drop contributions (inlet and outlet, channel, and wall). The predicted pressure drop shows a strong impact of the coating location and agrees well with the experiments.

The development of novel strategies for the prevention of bacterial infections is of utmost importance because of the exponential growth in the number of patient morbidity related to nosocomial and chronic infections. Nitric oxide (NO) is known to be a potent inhibitor of bacterial growth and adhesion to surfaces. Here, we develop an antibiofilm coating that possesses S-nitrosothiol NO donors via plasma polymerization (PP) for biofilm prevention applications. Cell culture dishes of four different film thicknesses ranging from 125 to 1000 nm were coated via PP using a thiol monomer. The thiol functionality on the substrates was converted to S-nitrosothiol NO precursors using tert-butyl nitrite. The successful conjugation of thiol and subsequent formation of S-nitrosothiol functionalities on the substrates were confirmed using X-ray photoelectron spectroscopy and UV–vis analysis. These coatings are capable of releasing NO over 2 days, and the NO loading is tunable by the polymer film thickness. The antibiofilm activity of the surfaces was assessed using Gram-negative bacteria, Pseudomonas aeruginosa. Higher film thickness (and hence, higher NO loading) demonstrate better antibiofilm activity, and the best performing coating shows 81 and 60% inhibition of bacterial attachment to the surface after exposure to bacterial culture solution for 24 and 36 h, respectively. Overall, the NO-releasing plasma-modified surfaces present a potential viable strategy to inhibit bacterial biofilm formation.