Nanopore-Level Wood-Water Interactions—A Molecular Simulation Study

Abstract

The nanoscale wood-water interaction strength, accessible sorption sites, and cell wall pore sizes are important factors that drive water sorption and the hysteresis phenomenon in wood. In this work, these factors were quantitatively studied using molecular simulations based on a cell wall pore model, previously developed by the authors. Specifically, the wall-water interaction strength, the sorption sites network including their number, interaction range, strength, and spatial distributions were set at a series of theoretical values as simulation input parameters. The results revealed that most of the investigated parameters significantly affected both sorption isotherms and hysteresis. Water monolayers and clusters were observed on the simulated pore surface when the wood-water interaction and sorption site strength were set at unrealistically high values. Furthermore, multiple linear regression models suggested that wood-water interaction and sorption site parameters were coupled in determining sorption isotherms, but not in determining hysteresis.