Contributions of Extractives and Lignin to the Fractal Geometry of Internal Wood Surfaces

Internal wood surfaces can be treated as fractals, which are between Euclidean geometry and complete randomness. The fractal dimension Dfs is very informative in investigating the roughness of the internal surfaces of wood. In this study, the water sorption isotherms, including adsorption and desorption isotherm, of untreated, benzene-alcohol extracted and delignified (after benzene-alcohol extracted) spruce (Cuninghamia lanceolata) were measured at 30℃. On the basis of these isotherms, the Dfs values were calculated by FHH equation, which is based on multimolecular sorption. The results showed that both groups of Dfs values (respectively calculated from adsorption and desorption isotherms) of untreated, benzene-alcohol extracted and delignified wood have same order, that is, untreated > benzene-alcohol extracted - delignified. Therefore, the conclusion can be made that the benzene-alcohol extractives have significant contribution to the fractal geometry of internal wood surfaces. Lignin also has influ

Contributions of Extractives and Lignin to the Fractal Geometry of Internal Wood Surfaces

Internal wood surfaces can be treated as fractals, which are between Euclidean geometry and complete randomness.The fractal dimension Dfs is very informative in investigating the roughness of the internal surfaces of wood. In this study, the watersorption isotherms, including adsorption and desorption isotherm, of untreated, benzene-alcohol extracted and delignified (after ben-zene-alcohol extracted) spruce (Cuninghamia lanceolata) were measured at 30℃. On the basis of these isotherms, the Dfs valueswere calculated by FHH equation, which is based on multimolecular sorption. The results showed that both groups of Dfs values (re-spectively calculated from adsorption and desorption isotherms) of untreated, benzene-alcohol extracted and delignified wood havesame order, that is, untreated ＞ benzene-alcohol extracted ≈ delignified. Therefore, the conclusion can be made that the ben-zene-alcohol extractives have significant contribution to the fractal geometry of internal wood surfaces. Lignin also has influence onthe fractal geometry, but this influence is very small while compared with that of the extractives. Moreover, the Dfs values calculatedfrom adsorption isotherms are bigger than those from desorption isotherms.