Fractal dimension of wood pores from pore size distribution

Abstract Understanding wood pore geometry and distribution is the basis for studying its macroscopic properties. This research investigated the pore fractal dimension using the pore size distribution of selected softwoods and hardwoods. Mercury intrusion porosimetry explored the detailed structural parameters of wood pore size distributions and assessed their fractal dimension. The results revealed significant variability in pore size distribution, porosity, pore volume, and fractal dimension values. The threshold pressure extracted from porosimetry data can be used as the main parameter to distinguish the pore size distribution regions. Pore sizes ranged from 3 to 35,000 nm, with a corresponding porosity that ranged from 58 to 76%. Three pore size classes were determined and ranged as: macropores (radius 350,000–5000 nm), mesopores (radius 5000–100 nm), and micropores (radius 100–3 nm). The fractal dimension values in the corresponding macropore, mesopore, and micropore size intervals were 2.98–2.998, 2.6–2.92, and 2.53–2.72, respectively, indicating a higher degree of complexity for larger pores.