Pore structure characterization of poplar tension wood by nitrogen adsorption-desorption method

Texte intégral en chinois, résumé en anglais.Based on the conventional anatomical analysis, the pore structures of poplar tension wood, such as specific surface area, pore volume and pore size distributions were characterized by nitrogen adsorption-desorption method. The shapes of the pores were estimated by nitrogen adsorption isotherms. The results show that poplar tension wood with BET specific surface area of 21.9 m2·g-1, which is 13 times higher than that in opposite wood. Poplar tension wood has intact mesoporosity (pore size between 2-50 nm) with inkbottle and slit shape pore, as well as a certain amount of micropores and macropores. The maximum value of pore size distribution appears at 5 nm. The pore volume with diameter ranging from 4-7 nm makes up 74.4% of the total, and larger than 15 nm, 10.8%. The high amount of mesopores can be attributed to the thick gelatinous layer in poplar tension wood