Summary
USDA Forest Service scientists used nanomechanical spectroscopy experiments to discover that chemical species like mineral ions diffuse through interconnecting pathways of rubbery amorphous polysaccharides (amorphous cellulose and hemicelluloses) in wood cell walls. This diffusion mechanism is in contrast to the nearly century-old assumption that such chemical species diffuse through simple interconnecting water pathways inside of cell walls. Identifying the diffusion mechanism opens up a new paradigm in wood research because the extensive polymer science literature can now be used to design the molecular architecture of wood cell walls to optimize diffusion properties for specific uses, including:
1. In the manufacture of engineered wood building materials, such as during adhesive bonding, wood preservative treatments, and bulk wood chemical modifications;
2. In decay and fastener corrosion degradation mechanisms in wood-based materials, as degradation of in-service wood materials is a major economic and conservation issue; and
3. In paper mills and biorefineries, where the diffusion of pretreatment chemicals and enzymes into cell walls is a critical process.