Andreas Treu
Head of Department/Head of Research
Biography
Dr. Andreas Treu has been a research scientist at NIBIO (formerly the Norwegian Forest and Landscape Institute) since 2006 and works in the Department of Wood Technology. He graduated from the University in Göttingen, Germany, with a doctoral degree in Forest Sciences and Forest Ecology. He works on wood protection, modification, and anatomy.
Abstract
Modifying natural polymers with silicones gives new possibilities for packaging products and waste management. In this study, the innovative papers produced were altered following the reaction of polysaccharides and organosilicon compounds. The susceptibility of the studied material to biodegradation caused by a brown-rot fungus was assessed. Strength properties by tensile strength and dynamic mechanical analysis and hydrophobic properties by water uptake test and water contact angle analysis were evaluated. Moreover, elemental analysis by ICP method was controlled. The durability against fungi and the hydrophobic properties were increased by the modification. The fungal decay resistance of the silanized paper was reduced by water storage, which allows for managing paper waste. Cellulose-based paper treated with starch-modified methyltrimethoxysilane showed potential as a packaging material due to its reduced water uptake. Possible application areas could be corrugated boxes, cellulose thermoformed products for electronics, and food packaging. However, the water-repellent effect is limited to short-term exposure in humid conditions.
Abstract
Wood modification using polyesterification of sorbitol and citric acid is a novel environmentally friendly strategy for wood protection improving its dimensional stability and acts against fungal deterioration. Inelastic Raman scattering is sensitive to the molecules of high polarizability and both lignocellulose and aliphatic esters formed during the treatment are polar. Therefore, in the present study, the quality control of the treatment using a handheld Raman spectrometer equipped with 830 nm laser is suggested as a rapid and reliable approach. Raman spectra from six wood modification levels (resulting in different weight percent gain, WPG) of three different wood species (Silver birch, Scots pine and Norway spruce) as well as three sample preparation strategies (intact, sanded and milled wood samples) were collected, and further analyzed using a chemometric method. Best performing models based on Powered Partial Least Squares Regression predicted the WPG level at R2 = 0.85, 0.95 and 0.98 for birch, pine and spruce, respectively. In addition, a clear separation between hard and soft wood species was also captured. Especially for softwood species, the sample preparation method affected the model accuracy, revealing the best performance in milled material. It is concluded that by using handheld Raman spectrometer it is possible to perform accurate quality control of wood modified by polyesterification of citric acid and sorbitol.
Abstract
No abstract has been registered
Authors
Andreas Treu Katrin Zimmer Christian Brischke Erik Larnøy Lone Ross Foued Aloui Simon M. Cragg Per-Otto Flæte Miha Humar Mats Westin Luisa Borges John WilliamsAbstract
Timber structures in marine applications are often exposed to severe degradation conditions caused by mechanical loads and wood-degrading organisms. This paper presents the use of timber in marine environments in Europe from a wood protection perspective. It discusses the use of wood in coastline protection and archeological marine wood, reviews the marine borer taxa in European waters, and gives an overview of potential solutions for protection of timber in marine environments. Information was compiled from the most relevant literature sources with an emphasis on new wood protection methods; the need for research and potential solutions are discussed. Traditionally, timber has been extensively utilized in a variety of marine applications. Although there is a strong need for developing new protection systems for timber in marine applications, the research in this field has been scarce for many years. New attempts to protect timber used in marine environments in Europe have mainly focused on wood modification and the use of mechanical barriers to prevent colonization of marine wood borers. The importance of understanding the mechanisms of settlement, migration, boring, and digestion of the degrading organisms is key for developing effective systems for protecting timber in marine environments.
Abstract
Wood has many attractive material qualities, but it is susceptible to biological degradation by wood-decaying fungi. Moisture is one of the critical requirements for wood decay, but much remains unknown about moisture dynamics in decaying wood. To fill this knowledge gap, this study investigated moisture in Scots pine sapwood during decay caused by the brown rot fungus Coniophora puteana. Samples were exposed to decay in two time-series experiments; mass loss and moisture content were recorded over the course of decay, and the bound and free water populations in the samples were analysed using low-field nuclear magnetic resonance (LFNMR) relaxometry in both the decaying state and at full water saturation. Selected samples were also used for water vapour sorption measurements. The time-series decay tests showed that moisture content initially increased due to fungal activity but decreased over time when corrected for mass loss, contrary to the general belief that moisture content increases with decay. LFNMR revealed that bound water content increased on a decayed-mass basis in the decaying state and at saturation, but no increase was seen after correction for mass loss. Free water content followed gravimetric moisture content in the decaying state, but the saturated state measurements revealed an initial increase and subsequent decrease with mass loss. Degradation caused changes in hygroscopicity, but our data show that overall moisture content is regulated by fungal activity rather than by material properties. These findings highlight the complexity of water interactions during fungal degradation, offering valuable new insights into wood degradation mechanisms.
Authors
Gry Alfredsen Lone Ross Atle Wehn Hegnes Michael Altgen Andreas Treu Sverre Aarseth Tunstad Igor A. Yakovlev Mari Sand Austigard Johan Mattson Maria Paz Nunez Garcia Anne Cathrine Flyen Cecilie Flyen Trine Mathea Skjeltorp Nanna Bjerregaard PedersenAbstract
Prosjektet «ArcticAlpineDecay» har undersøkt hvordan klimaendringer og økt menneskelig aktivitet påvirker trebasert kulturarv i arktiske og alpine miljøer, med fokus på Svalbard og Finse. Resultatene viser at lengre perioder med varme og fuktighet gir bedre vekstvilkår for råtesopper og øker risikoen for biologisk nedbrytning. Samtidig forsterker økt ferdsel slitasjen på sårbare kulturmiljøer, særlig på Svalbard hvor mange kulturminner er vanskelige å identifisere og tåler lite påvirkning. Fire faktorer øker risikoen for skader i kulturmiljøene: vanskelig lesbarhet, dårlig teknisk tilstand, spennende detaljer og høy tilgjengelighet. Det er funnet omfattende råte nær bakken, og DNA-analyser viser et stort mangfold av vednedbrytende sopper, inkludert arter som ikke tidligere er dokumentert i polarområder. Alvorlig soppnedbrytning oppstår etter rundt 50 år, noe som betyr at taubanebukker med eldre fundamenter nå er kritisk nært restaureringsbehov. For Finse og Hardangervidda er de største utfordringene økt bruk, manglende kunnskap og fysisk slitasje. Det anbefales økt informasjon til turister og guider, enkel fysisk tilrettelegging, bedre overvåking og kombinasjon av metoder for å avdekke både overflate- og indre råteskader, samt videre forskning.
Abstract
No abstract has been registered
