Probing nanoscale protection mechanisms with x-rays and neutrons
| Authors: | Nayomi Z. Plaza, Katie M. Ohno, Joseph Jakes, James B. O'Sullivan, Lin Yang |
| Year: | 2025 |
| Type: | Paper |
| Station: | Forest Products Laboratory |
| Source: | IRG paper |
Abstract
While it is known that exposing wood to high levels of moisture, fire, or decay agents such as fungi can be detrimental for its performance, what is often missing in literature is a holistic understanding of how wood nanostructure changes due to these exposures. This is of particular interest since treatments that are meant to impart resistance can alter these length scales and/or modify their hygroscopic behavior. Yet, our knowledge of how protection treatments, such as chemical modification, alter the wood nanostructure is limited. X-ray and neutron scattering techniques are uniquely suited to probe these questions but remain underutilized in wood research. Small angle scattering can be used to measure the extent of chemical infiltration in the cell walls as well as the nanoscale swelling, while wide-angle scattering can probe changes in the cellulose crystalline structure. By combining these techniques, key nanoscale features that correlate with wood macroscale properties have been identified. For instance, model degraded woods with diminished mechanical properties had increased nanoscale disorder and swelling, while decay resistant chemically modified woods had reduced nanoscale swelling, and nanoscale features that were resistant to fungal exposure. An overview of the techniques as well as perspectives on the opportunities for their use in future wood protection research will be provided.