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- Englisch (2)
Schlagworte
- Coniophora puteana (2) (entfernen)
Organisationseinheit der BAM
- 4 Material und Umwelt (1)
- 4.1 Biologische Materialschädigung und Referenzorganismen (1)
- 4.3 Schadstofftransfer und Umwelttechnologien (1)
- 5 Werkstofftechnik (1)
- 5.1 Mikrostruktur Design und Degradation (1)
- 6 Materialchemie (1)
- 6.3 Strukturanalytik (1)
- 8 Zerstörungsfreie Prüfung (1)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (1)
Decay resistance of pine sapwood treated with titanium alkoxide solutions was tested against the brown-rot fungi Coniophora puteana and Poria placenta for exposure times of 10 and 16 wk. In practice, wood-specimens were vacuum-impregnated by alcoholic solutions of titanium alkoxide with concentrations in the range of 5–16 mass % (solid content in solution) and subsequently cured under different humidity conditions. Results reveal that treated wood degraded up to 5% in comparison to untreated one that deteriorated 38% and 50%, respectively against both wood-decay fungi. Even full protection (mass loss below 3%) was achieved against brown rot with titanium alkoxide solution containing solid content of around 5 mass% with a weight percentage gain (WPG) of 9 mass%. With increased concentration, fungal resistance decreased slightly which was associated with more cracks and imperfections formed in the deposited layers of titanium dioxide in the adjacent wood matrix. Thermal analysis verified that a considerable amount of precursor remained in the wood structure as un-hydrolyzed organic residues. These organics, being bioactive, had the tendency to induce similar fungicidal effects as those of conventional fungicides. The amount of organic residues is correlated with the decay resistance of the tested samples. In a prolonged decay test, mass losses of 16-wk incubated samples do not show behavior different from that of the wood samples incubated for 10 wk. This result implies that the decay protection is permanent and confirms further the fungicidal activity of titanium-alkoxide-treated wood.
Wood treated with nano metal fluorides is found to resist fungal decay. Sol−gel synthesis was used to synthesize MgF2 and CaF2 nanoparticles. Electron microscopy images confirmed the localization of MgF2 and CaF2 nanoparticles in wood. Efficacy of nano metal fluoride-treated wood was tested against brown-rot fungi Coniophora puteana and Rhodonia placenta. Untreated wood specimens had higher
mass losses (∼30%) compared to treated specimens, which had average mass loss of 2% against C. puteana and 14% against R. placenta, respectively. Nano metal fluorides provide a viable alternative to current wood preservatives.