A novel approach for characterizing pore size distribution of wood cell wall using differential scanning calorimetry thermoporosimetry

The pore size distribution (PSD) of cell wall is crucial for the wood, which could be investigated by the heat absorption of cell wall water upon melting. This study proposed a novel approach to characterize continuous cell wall PSD by solving the differential equation of the water amount melting inside wood obtained from the differential scanning calorimetry (DSC). Compared with the method using the isothermal process, this approach gained a more accurate PSD, and overcome the disadvantages of long-time measurement. Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) was investigated with this novel method. The results showed that the pore volume decreases sharply with the increase of pore size, and the cell wall pores above 20 nm hardly existed. The relation between cell wall pore size and volume had the similar trend between the above two methods. However, there was a quantity gap in pore volume of 9.4–52.4 times between two methods.