S. Benfer, J.Z. Bloh, S. Funk, C. Langer, S. Läufer, S. Lederer, A. Pashkova, E.B. Sa, W. Fürbeth
Prof. Dr. Timo Sörgel (Hrsg.), Jahrbuch Oberflächentechnik 2022 - Band 78, Eugen G. Leuze Verlag, Bad Saulgau (2012) 259-273
One of the main problems for air quality in cities is pollution by nitogen oxides (NOx). In order to reduce the nitrogen oxides, facade cladding should be provided with photocatalytic properties by incorporating titanium dioxide nanoparticles. For this purpose, anodizing processes were developed for the facade alloy EN-AW-5005, in which highly ordered anodized structures with a low degree of arborizaton and tortuosity are produced. Pore widths between 10 nm and 60 nm with layer thicknesses of about 2-3 µm are obtained. The subsequent impregnation was carried out by means of electrophoretic deposition (EPD) from solvent-based systems. Depending on the EPD parameters and the suspension used, the pores can be completely filled. The photocatalyric activity tested according to ISO 22197-1 certifies that the impregnated anodized coatings show a high photocatalytic activity with rPCE values of up to 13, with rPCE>2 being "photocatalytically active for air purification". Tests on the corrosion resistance of the anodized coatings to a commercially available aluminum and facade cleaner confirm the protective effect of the anodized coatings compared to the non-anodized material. The impregnation with the photocatalytic active TiO2 particles reinforces this protective effect similar to a subsequent densification.