Nanoscale Wood Surface Properties by Adhesion-Force AFM
Abstract
Wood is the most important renewable resource and it is used in huge quantities for load bearing structures, pulping and papermaking. Wood is characterized by its excellent strength to weight ratio which is based in cellular composition and hierarchical design. Hereby the cell wall composition, especially the distribution and interaction of the structural polymers at the nanoscale level is not fully understood. Recently significant differences in the local binding situation to different wood cell wall elements within adhesive bonds leaded to own preliminary studies performed by atomic force microscopy (AFM) based adhesion-force mapping measurements. The gained results showed significant higher adhesion-forces on the secondary cell wall S2 compared to native inner lumen surfaces, which were attributed to differences in polarity of the individual cell wall regions. Based on these preliminary findings, a systematic study on the observed effects is proposed using adhesion-force mapping, a state of the art AFM technique not yet established in wood material science. In a first step fundamental differences in wood surface properties of wood cell wall elements will be addressed. Moisture is seen as main biasing factor to control the contrast induced by in polarity. Later on contrast originated by surface charge density will be used as driving force. With the help of this method the local variability of properties of the wood cell wall components will be investigated and shall be attributed to the individual cell wall polymers. By looking at the wood surface from this new perspective, we hypothesize to contribute to a better understanding of the cell wall composition at the nanoscale and additionally increase the understanding of different adhesion phenomena of the various interface types available in wood bonds.
keywords Atomic force microscopy Polarity adhesion Wood Surface
Publikationen
Project staff
Johannes Konnerth
Univ.Prof. Dipl.-Ing. Dr. Johannes Konnerth
johannes.konnerth@boku.ac.at
Tel: +43 1 47654-89159
Project Leader
01.11.2014 - 31.10.2019