Yan Wenjing, Qing Yan, Li Zhihan, Li Lei, Luo Sha, Wu Ying, Chen Deng, Wu Yiqiang, Tian Cuihua
College of Materials Science and Technology, Central South University of Forestry and Technology, Changsha 410004, China.
Molecules. 2024 Feb 21;29(5):938. doi: 10.3390/molecules29050938.
The construction of networks within natural wood (NW) lumens to produce porous wood aerogels (WAs) with fascinating characteristics of being lightweight, flexible, and porous is significant for the high value-added utilization of wood. Nonetheless, how wood species affect the structure and properties of WAs has not been comprehensively investigated. Herein, typical softwood of fir and hardwoods of poplar and balsa are employed to fabricate WAs with abundant nanofibrillar networks using the method of lignin removal and nanofibril's in situ regeneration. Benefiting from the avoidance of xylem ray restriction and the exposure of the cellulose framework, hardwood has a stronger tendency to form nanofibrillar networks compared to softwood. Specifically, a larger and more evenly distributed network structure is displayed in the lumens of balsa WAs (WA-3) with a low density (59 kg m), a high porosity (96%), and high compressive properties (strain = 40%; maximum stress = 0.42 MPa; height retention = 100%) because of the unique structure and properties of WA-3. Comparatively, the specific surface area (SSA) exhibits 25-, 27-, and 34-fold increments in the cases of fir WAs (WA-1), poplar WAs (WA-2), and WA-3. The formation of nanofibrillar networks depends on the low-density and thin cell walls of hardwood. This work offers a foundation for investigating the formation mechanisms of nanonetworks and for expanding the potential applications of WAs.
在天然木材（NW）管腔内构建网络以制备具有轻质、柔性和多孔等迷人特性的多孔木材气凝胶（WAs），对于木材的高附加值利用具有重要意义。然而，木材种类如何影响WAs的结构和性能尚未得到全面研究。在此，采用杉木典型软木以及杨树和轻木典型硬木，通过去除木质素和纳米纤维原位再生的方法制备具有丰富纳米纤维网络的WAs。得益于避免了木射线限制和纤维素框架的暴露，与软木相比，硬木形成纳米纤维网络的趋势更强。具体而言，由于WA - 3独特的结构和性能，低密度（59 kg/m³）、高孔隙率（96%）和高压缩性能（应变 = 40%；最大应力 = 0.42 MPa；高度保留率 = 100%）的轻木WAs（WA - 3）管腔内呈现出更大且分布更均匀的网络结构。相比之下，杉木WAs（WA - 1）、杨树WAs（WA - 2）和WA - 3的比表面积（SSA）分别增加了25倍、27倍和34倍。纳米纤维网络的形成取决于硬木的低密度和薄壁细胞。这项工作为研究纳米网络的形成机制以及拓展WAs的潜在应用提供了基础。
