TEMPO氧化处理调控轻木细胞壁纳米结构  

Regulating Balsa Wood Cell Wall Nanostructure via TEMPO Oxidation

作　　者：吴明月 戴鑫建 王鑫 王小青[1] WU Mingyue;DAI Xinjian;WANG Xin;WANG Xiaoqing(Research Institute of Wood Industry,Chinese Academy of Forestry,Beijing 100091,China)

机构地区：[1]中国林业科学研究院木材工业研究所,北京100091

出　　处：《木材科学与技术》2024年第6期1-7,共7页Chinese Journal of Wood Science and Technology

基　　金：“十四五”国家重点研发计划课题“木竹材细胞壁多层级结构与构效调控机制”(2023YFD2200501)。

摘　　要：针对天然木材细胞壁中纳米孔隙有限及比表面积低的问题,采用2,2,6,6-四甲基哌啶-1-氧自由基(2,2,6,6-tetramethylpiperidinyl-1-oxyl radical,TEMPO)介导氧化法原位疏解轻木(Ochroma pyramidale)细胞壁微纤丝束,并结合超临界干燥制备TEMPO氧化木材,以调控木材细胞壁纳米结构并提升其比表面积。采用扫描电镜(SEM)、傅里叶变换红外光谱仪(FTIR)及能量色散能谱仪(EDS)对材料的微观形貌和化学组成进行表征,并结合比表面积及孔隙度分析仪,探究氧化处理对木材细胞壁孔隙结构的影响。结果表明:TEMPO氧化处理保留了木材的蜂窝状细胞结构,并实现了木材细胞壁微纤丝束的原位疏解,使其展现高度纤丝化的纳米网络结构,纤丝直径分布在20~40 nm之间;TEMPO氧化处理木材细胞壁具有丰富的介孔结构,其比表面积高达96.92 m2/g,相比天然木材提升约72倍。研究为木材细胞壁纳米结构调控以及木基多孔材料开发提供新思路。The lack of nanopores and low specific surface area of natural wood limit its functional applications in many fields.In this study,2,2,6,6-tetramethylpiperidinyl-1-oxyl radical(TEMPO)-mediated oxidation was applied to generate nanopores in wood and increase its specific surface area by insitu fibrillation of cellulose microfibril bundles within the cell walls of balsa wood(Ochroma pyramidale).The microstructure and chemical composition of the TEMPO-oxidized wood were characterized using scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FTIR),and energy dispersive spectroscopy(EDS).Moreover,the effect of TEMPO-oxidation treatment on the pore structure of wood cell wall was investigated using a specific surface area and pore size analyzer.The results showed that the honeycomb-like cellular structure of the wood was well preserved after oxidation treatment,while the microfibrils in the wood cell wall were successfully individualized,resulting in a highly nanofibrillated network structure with microfibril diameters ranging from 20 to 40 nm.The TEMPO-oxidized wood exhibited a highly mesoporous structure with a high specific surface area of 96.92 m²/g,which is about 72 times higher than that of natural wood.This study provides a novel approach to regulating the nanostructure of wood cell walls for developing porous wood-based materials.

关 键 词：轻木 细胞壁纳米结构 细胞壁孔隙 TEMPO氧化 纤维素微纤丝 

分 类 号：S781[农业科学—木材科学与技术]