News
Categories
Recent Articles
IAWS met at the 67th SWST International Convention, Slovenia
IAWS met at the SWST Convention
IAWS held a special session at 67th SWST International Convention, June 30 – July 5, 2024, at the Grand Hotel Bernardin, Portorož, Slovenia.
THE SIGNIFICANCE OF BASIC WOOD SCIENCE IN A SUSTAINABLE WORLD
Chair: Rupert Wimmer (BOKU, Austria) - organized by IAWS
Abstracts
13:45-14:45 Ingo Burgert (ETH Zurich, Switzerland) "Wood materials - potentials and limitations" (Academy Lecture)
Wood's renewable nature and CO2 storage capacity have sparked a growing scientific interest in functional wood materials development. Exciting opportunities arise from modifying and functionalizing wood to take advantage of its hierarchical structure. Wood has a porous and anisotropic structure, providing excellent mechanical properties. This makes it an ideal biomaterial for developing high-performance composites and hybrid materials. Wood treatments can lead to wood materials with improved properties or new functions. The presentation will cover recent concepts and approaches for obtaining such wood materials. A further focus will be on anticipated changes in the provision of the resource wood and the various applications of wood in the future. In this respect, the presentation will discuss the potential and limitations of wood in becoming a key resource for a net-zero society.
Keywords: functionalisation, hierarchical material, biomaterial, modification
14:50-15:10 Katarina Čufar (University of Ljubljana, Slovenia) "Wood anatomy and dendrochronology - a long tradition and current challenges"
At the session of the International Academy of Wood Science (IAWS) we want to give an overview of the importance of wood anatomy and dendrochronology for a variety of research topics related to wood and (forest) trees. We will focus on the general challenges of wood anatomy and dendrochronology and illustrate them with some case studies in Slovenia, where the SWST conference will take place. Wood anatomy, organized in the International Association of Wood Anatomists (IAWA) founded in 1931, has traditionally provided the knowledge of wood characteristics required for wood identification. In recent decades, wood anatomy has become increasingly popular and in demand by an interdisciplinary community, and the number of IAWA members has doubled. The situation is similar with dendrochronology and the tree ring societies TRS and ATR. Currently, the classical wood anatomy, based on a variety of microscopy techniques, improved sample preparation and supported by new techniques such as isotope and DNA analyses and other analytical methods, continues to be a fundamental research tool. Important topics include activities to prevent illegal logging and the illegal trade in timber and wood products, from for instance charcoal to high-value musical instruments. Wood anatomy is also used to assess the wood properties of lesser-known species that are often planted outside their natural environment or spread as invasive alien tree species. Dendrochronology, with the basic aim to determine in which year the individual annual rings in the wood were formed by the cambium, is also a fundamental tool for answering numerous research questions, including the ones related to climate change effects. Dendrochronology is often combined with wood anatomy to maximize the benefits of both disciplines. With the increasing decline of trees and forests due to climate change, wood anatomy and dendrochronology have proven valuable for assessing wood quality and properties at an annual resolution. In ecophysiological studies, the two disciplines help to identify early warning signals and monitor the progression of tree decline, among other things. For trees growing under changing climatic conditions, studies on wood formation have enabled the “calibration” of dendrochronology and a better understanding of the wood structure formed under certain conditions. Finally, wood anatomy and dendrochronology are essential for the study of historical and archaeological wood, which we will demonstrate through case studies on historical objects in Piran and objects from the nearby archaeological sites.
Keywords: Wood Anatomy, Dendrochronology, Wood Technology, Trees, Climate Change, Historical Wood
15:10-15:30 Bohumil Kasal (Fraunhofer WKI, Germany)
"Materials from renewable resources - great future or just a modern trend? Are they really sustainable?"
During the last decade our environmental awareness has increased significantly and sustainability has become a frequently used term. Materials from renewable resources have become synonyms for sustainable solutions. The only truly renewable resources are plants that use photosynthesis to produce biomass. The capacity of the planet to produce biomass is not unlimited and is severely compromised by human activity. Using renewable resources to produce various materials, including building materials, does not automatically mean that these processes are sustainable or the products recyclable. This presentation will focus on global challenges with respect to the sustainability of using lignocellulosic natural resources in the production and use of materials with focus on building materials.
Keywords: Sustainability, renewable resources, biomass production, lignocellulosic materials
15:30-15:50 Markus Rűggeberg (Technical university in Dresden, Germany) "The dimensional instability of wood - a new look on an old problem"
The swelling and shrinking of wood is commonly regarded as a challenge and limiting factor in the utilisation of wood. However, it can also be seen as a material inherent capacity for generating curvature and actuation when used in a smart way. Differential fibre orientation in the two layers of a wooden bilayer allows for the manufacturing of humidity-driven, autonomous actuators, as well as curved elements for furniture or construction elements by an innovative self-forming process rather than with heavy machinery and large external forces. The curvature and residual stresses of such wooden bilayers can be predicted by simulation routines utilising different analytical or numerical models. The presentation will discuss potential applications, challenges and future directions.
Keywords: Wood swelling, shrinking, fiber orientation, Humidity-driven actuator, self-forming, simulation model
15:50-16:10 Andreas Krause (Thünen Institute, Germany), Martin Nopens, Imke Greving and Silja Flenner, "Swelling of wood cell wall - in 3D at high resolution"
The swelling and shrinking of wood is a main problem in many applications. This material property has been widely investigated in different studies at the macroscopic level. The reason for the macroscopic behaviour is caused by dimensional change at cell wall level, where the measurement of dimensional change is much more complicated. The aim of the study is to measure the swelling and shrinking at the level of single cells or fragments of cells in all three dimensions at nanometre resolution. For this purpose, a specialized climate chamber was designed, which can be installed at the imaging beamline P05 (nano-end-station) of the synchrotron source Petra III (DESY). After designing, manufacturing and testing of this climate chamber, small fragments of pine sapwood were measured at various states of temperature and relative humidity. The results show the complex 3D deformation in swelling and shrinking of small fragments of wood. An interesting effect could be observed that the cells / cell walls show twisting during moisture change, which is probably caused by the microfibril angle. This twist is not observed at macroscopic level and indicates an internal stress during dimensional changes. The evaluation of the volumetric amount of dimensional change is complex. Several methods show different results. This shall be evaluated further in future.
Keywords: Imaging, swelling, hygroscopic properties, microfibrils
16:10-16:30 Juan Li (Fraunhofer WKI, Germany) "Aging of wood as a construction material measured by atomic force microscopy
Wood has been utilized as a construction material since ancient times, with structures enduring for centuries under dry conditions. Combining lignocellulosic materials with concrete reduces structural mass, reuses waste, enhances ductility, and lowers construction costs. However, the compatibility and aging of such composite materials present challenges due to technological and environmental factors. This research investigates the aging mechanisms of wood surfaces under thermal and cement alkaline conditions at the nanoscale using atomic force microscopy (AFM) and other analytical techniques. The study aims to (1) develop and establish AFM measurement methods for wood surfaces, and (2) apply these methods to analyze aging at the cell wall level. By using an identical AFM tip to measure the same wood surface areas before and after treatment, the study provides insights into the aging process. The methods and findings are expected to be broadly applicable to all lignocellulosic materials.
Keywords: Lignocellulosics, composite, Aging mechanism, atomic force microscopy, Durability
