Miklós Bak

Biological resistance of pine wood treated with nano-sized zinc oxide and zinc borate against brown-rot fungi

In this work, the biological resistance of Scots pine (Pinus sylvestris L.) wood impregnated with nano-sized zinc oxide and zinc borate against the fungi Daedalea quercina, Poria placenta and Serpula lacrymans was evaluated. It can be concluded that nano-sized zinc oxide inhibited the biological degradation of pine wood against Serpula lacrymans, while it was ineffective against the brown-rot fungus Poria placenta. Pine wood treated with nano-sized zinc borate exhibited higher biological resistance against the fungi Serpula lacrymans and Poria placenta.

Improvement of dimensional stability of wood by silica nanoparticles

ABSTRACT The improving effect of nanoparticles on wood dimensional stability is barely known nowadays. The expected result of the research was the improvement of the dimensional stability through bulk hydrophobization, as a result of impregnation with hydrophobic SiO2 nanoparticles. Two different wood species, beech (Fagus sylvatica) and scots pine (Pinus sylvestris) were investigated. Two different treatments with silica nanoparticles were used. One treatment was a pure emulsion of modified (hydrophobized) silica nanoparticles (carrier material: ethanol), and another one was modified (hydrophobized) silica nanoparticles in tetrahydrofuran carrier material in combination with polydimethylsiloxane (PDMS) as a bonding agent. PDMS was used to improve the bonding of the silica nanoparticles to the wood structure. The impregnation with nanoparticles was successful. Shrinking and swelling properties decreased by 17–33%, depending on wood species and treatment. Water uptake and equilibrium moisture content decreased significantly as a result of the treatments (40–58%). Application of PDMS did not provide better dimensional stability compared to the treatment without it, however, it resulted in lower equilibrium moisture content and water uptake compared to the basic nano-SiO2 treatment.The improving effect of nanoparticles on wood dimensional stability is barely known nowadays. The expected result of the research was the improvement of the dimensional stability through bulk hydro...