木基材料自上而下多尺度结构设计研究进展

ADVANCES IN TOP-DOWN MULTISCALE STRUCTURAL DESIGN OF WOOD-BASED MATERIAL

在全球气候变暖危机和“双碳”战略的大背景下,开发使用木基材料替代传统结构或功能材料,可以大大降低能源消耗,减少碳排放并增加碳封存量,对改善生态环境、实现绿色可持续发展具有重大意义.近年来,为了开发利用木质资源并提升传统木基材料的宏观性能,不少学者通过自上而下的“两步改性”策略实现了木材中从微观尺度到宏观尺度的多尺度结构设计调控,从而赋予了木基材料诸如高强度等不同的宏观性能,为开发设计可持续、绿色低碳的高性能木基材料开辟了新的天地.基于此,文章围绕木基材料中自上而下的多尺度结构设计策略进行了详细综述:首先简要概述了木材天然具备的跨尺度多层级结构,接着综述了微观尺度下木基材料中由纤维素主导的力学行为机制,其次从细胞壁工程的角度回顾了不同微结构调控策略以及得到的具有不同性能的木基材料,随后简要综述了近期木基材料的功能化应用新进展.最后总结了现有木基材料多尺度结构设计方面存在的不足并提出了相应的研究展望.

In the context of the global warming and the"carbon peaking&carbon neutrality"strategy,it is necessary to develop and use wood-based materials as an alternative to traditional structural and functional materials as a means to reduce energy consumption and greenhouse gas emissions,as well as to increase global carbon storage as consequence.Such development and replacement are of great significance for the preservation of the natural environment and for the achievement of a sustainable development in human society.During the past few years,in order to develop and utilize abundant wooden resources and improve the macroscopic performance of traditional wood-based materials,many researchers have been successful in achieving multiscale structural design and control from the microscale to the macroscale in natural wood with a top-down"two-step modification"approach.By modifying wood-based materials in such a way,researchers successfully equipped wood with various excellent macroscopic properties such as high mechanical strength,thus opening up a new field for developing and designing environmentally friendly high-performance wood-based materials that are sustainable and green.On the basis of such a background,this paper presents a review of recent top-down multi-scale structural design strategies for wood-based materials.First of all,there was a brief introduction to the inherent hierarchical structure of natural wood.Then,at microscale,the mechanical behavior and mechanism dominated by cellulose in high-performance wood-based materials were discussed.Subsequently,different strategies for modifying and regulating wood microstructures and the corresponding obtained wood-based materials with different macroscopic properties were reviewed from the perspective of cell wall engineering.Finally,a brief review of the latest developments in functionalized use of wood-based materials was presented.At the end of this paper,a summary of the insufficiency of existing multiscale structural design and modification strategies of wood-based materials was concluded,and the corresponding research prospects were given as potential solutions.