Characterization of a gel in the cell wall to elucidate the paradoxical shrinkage of tension wood
Characterization of a gel in the cell wall to elucidate the paradoxical shrinkage of tension wood
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DOI：
10.1021/bm700987q
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发表时间：
2008-02-01
影响因子：
6.2
通讯作者：
Quignard, Francoise
中科院分区：
文献类型：
--
作者：
Clair, Bruno;Gril, Joseph;Quignard, Francoise
木材的行为具有高度的湿度敏感性和强烈的各向异性。纤维的干燥收缩通常很小，这是由于纤维素微纤维的增强作用，而在所谓的张力木材中，这种木材的干燥收缩出人意料地高，这种木材是由树木产生的，以响应强烈的重新定向要求。本研究中，超临界干燥木材和普通木材的氮气吸附-脱附等温线表明，拉伸木材细胞壁具有凝胶状结构，其孔表面是普通木材的30多倍。拉伸木材凝胶的水合作用解释了其矛盾的干燥收缩。这一结果有助于减少干燥过程中的技术问题。考虑到在活的树木中，受拉木材产生的拉伸生长应力是正常木材的10倍，因此在生物力学和仿生方面的潜在应用值得研究。
Wood behavior is characterized by high sensibility to humidity and strongly anisotropic properties. The drying shrinkage along the fibers, usually small due to the reinforcing action of cellulosic microfibrils, is surprisingly high in the so-called tension wood, produced by trees to respond to strong reorientation requirements. In this study, nitrogen adsorption-desorption isotherms of supercritically dried tension wood and normal wood show that the tension wood cell wall has a gel-like structure characterized by a pore surface more than 30 times higher than that in normal wood. Syneresis of the tension wood gel explains its paradoxical drying shrinkage. This result could help to reduce technological problems during drying. Potential applications in biomechanics and biomimetics are worth investigating, considering that, in living trees, tension wood produces tensile growth stresses 10 times higher than that of normal wood.