WOOD RESEARCH Volume 62, Number 1, 2017
Ladislav Reinprecht and Zuzana Vidholdová

Growth inhibition of moulds on wood surfaces in presence of nano-zinc oxide and its combinations with polyacrylate and essential oils

The paper deals about an anti-mould efficiency of nano-zinc oxide applied into wood alone (0.1%, 0.33%, 1% and 3% ZnO) or in combination with polyacrylate (5% Paraloid B-72) and essential oils (1% and 3% clove, oregano or thyme oil). Treatment of lime tree and maple samples 50×10×5 mm (L×R×T) with these chemicals was performed by one-step or two-step dipping at 20 °C/1 h. The anti-mould efficiency of used chemicals was determined by the standard STN 49 0604 – evaluating effect of chemicals against growth of four moulds (mixture of Alternaria alternata, Aspergillus niger, Penicillium brevicompactum and Chaetomium globosum) in the 7th 14th, 21st and 28th day. The anti-mould efficiency of ZnO nanoparticles was relatively poor, however, it was evidently improved in presence of clove and oregano oils, mainly in the first 7 days of the mould test.

WOOD RESEARCH Volume 63, Number 4, 2018
Stanislav Doubek, Vlastimil Borůvka, Aleš Zeidler, and Ladislav Reinprecht

Effect of the passive chemical modification of wood with silicon dioxide (silica) on its properties and inhibition of moulds

This work investigates how wood modification with silicon dioxide affects its selected physical and mechanical properties and resistance to moulds. Silicon mineralization can improve some of the technical properties of wood and extend the service-life of wooden structures. Silicon, which is contained in inorganic and organic-inorganic substances that are used for artificial wood mineralization or is the main component at natural wood mineralization, was used in the form of colloidal silicon dioxide and its various concentrations for pressure impregnation of beech (Fagus sylvatica) and Silver fir (Abies alba) wood samples. Following, physical, mechanical and biological properties of such modified woodswere tested together with waterlogged fir wood stored in water over a long period. Silicon-dioxide did not significantly improve properties of beech and fir woods, probably due to the hypothesis, that none covalent bonds between the silicon and the OH- groups of cellulose, hemicelluloses or lignin could be created in the cell-walls of the silicon-modified woods.

WOOD RESEARCH Volume 63, Number 3, 2018
Ján Iždinský, Ladislav Reinprecht, and Erik Nosáľ

Antibacterial efficiency of silver and zinc-oxide nanoparticles in acrylate coating for surface treatment of wooden composites

The paper deals with antibacterial effect of silver and zinc-oxide nanoparticles in acrylic coatings applied at treatment of commercial wooden composites – particleboard and medium density fibreboard. The silver nanoparticles usually better suppressed the activity of the Gramnegative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus already at lower concentrations (0.04 – 0.2 mg Ag/100 g of coating) as the zinc-oxide nanoparticles used in 100-times higher concentrations (4 – 20 mg ZnO/100 g of coating). Both types of applied nanoparticles at higher concentrations had a more apparent efficiency against E. coli comparing to S. aureus.