부산대학교 도서관

Abstract The improved fungal decay resistance exhibited by modified wood has been attributed to inhibited diffusion of decay precursors and subsequent degradation products through the wood cell wall. However, data relating the effect of modification to diffusion through wood cell walls is lacking. Synchrotron X-ray fluorescence microscopy paired with an in situ humidity chamber was used to observe the transport of an implanted model metabolite, potassium (K+) ions, in wood cell walls as a function of relative humidity (RH) and extent of the wood modification acetylation. The RH threshold for K+ transport in wood cell walls increased with increasing levels of acetylation between 0 and 20 wt percentage gain (WPG), which clearly indicates that acetylation inhibits ion transport in the modified wood cell walls. The reduced equilibrium moisture content (EMC R or moisture based on wood polymer mass) thresholds were also calculated, but the trend of EMC R thresholds with WPG was inconclusive. Although the results provided support to the proposed mechanism that diffusion inhibition in acetylated wood caused decay resistance, the results could not confirm that diffusion inhibition was the most important mechanism. The observed inhibition of K+ transport in acetylated wood should motivate additional work to understand how chemical modifications affect cell wall diffusion and the implications for producing decay-resistant wood. Graphical abstract Image 1 Highlights • Relative humidity thresholds for K+ diffusion were determined in acetylated wood. • Ion mobility was first observed at 60–75% RH in control and 92–95% RH for 20 WPG. • This is the first data to confirm that diffusion is inhibited by acetylation. • Results support that inhibiting diffusion may be the mechanism of decay resistance. [ABSTRACT FROM AUTHOR]