Department of Wood Anatomy and Utilization, Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091, China.
Wood Collections (WOODPEDIA), Chinese Academy of Forestry, Beijing 100091, China.
Molecules. 2020 Mar 3;25(5):1113. doi: 10.3390/molecules25051113.
Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.
对水涝考古木材（WAW）中完好的细胞壁（VICWs）进行了结构和化学降解及其对细胞壁力学性能的影响研究。通过无需预先嵌入的纳米压痕法来检查细胞壁的机械性能。WAW 的硬度和弹性模量均下降了 25%以上。通过 ATR-FTIR 成像、拉曼成像、湿化学、C-固态 NMR、热解-GC/MS、广角 X 射线散射和 N 氮吸附研究了细胞壁成分、纤维素微晶结构和孔隙率的变化。WAW 中的 VICWs 具有木聚糖侧链羧基的断裂、多糖的严重损失以及木质素中β-O-4 键的部分断裂。这伴随着细胞壁中中孔数量的增加。即使在 WAW 中的 VICWs 在纳米尺度上也受到严重破坏，从而影响了力学性能，这对考古沉船的保护具有重要意义。
