Xu Xiaoying, Garemark Jonas, Ram Farsa, Wang Zhen, Li Yuanyuan
Wallenberg Wood Science Center, Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
ACS Appl Mater Interfaces. 2024 May 1;16(17):22433-22442. doi: 10.1021/acsami.4c02779. Epub 2024 Apr 18.
Metallic wood combines the unique structural benefits of wood and the properties of metals and is thus promising for applications ranging from heat transfer to electromagnetic shielding to energy conversion. However, achieving metallic wood with full use of wood structural benefits such as anisotropy and multiscale porosity is challenging. A key reason is the limited mass transfer in bulk wood where fibers have closed ends. In this work, programmed removal of cell-wall components (delignification and hemicellulose extraction) was introduced to improve the accessibility of cell walls and mass diffusion in wood. Subsequent low-temperature electroless Cu plating resulted in a uniform continuous Cu coating on the cell wall, and, furthermore, Cu nanoparticles (NPs) insertion into the wood cell wall. A novel Cu NPs-embedded multilayered cell-wall structure was created. The unique structure benefits compressible metal-composite foam, appealing for stress sensors, where the multilayered cell wall contributes to the compressibility and stability. The technology developed for wood metallization here could be transferred to other functionalizations aimed at reaching fine structure in bulk wood.
金属木材结合了木材独特的结构优势和金属的特性，因此在从热传递到电磁屏蔽再到能量转换等一系列应用中具有广阔前景。然而，要充分利用木材的结构优势（如各向异性和多尺度孔隙率）来制备金属木材具有挑战性。一个关键原因是在纤维末端封闭的块状木材中传质受限。在这项工作中，引入了细胞壁成分的程序性去除（脱木质素和半纤维素提取），以提高细胞壁的可及性和木材中的质量扩散。随后的低温化学镀铜在细胞壁上形成了均匀连续的铜涂层，此外，铜纳米颗粒（NPs）插入到木材细胞壁中。创建了一种新型的嵌入铜纳米颗粒的多层细胞壁结构。这种独特的结构有利于可压缩金属复合泡沫，对应力传感器具有吸引力，其中多层细胞壁有助于可压缩性和稳定性。这里开发的木材金属化技术可以转移到其他旨在实现块状木材精细结构的功能化处理中。
