Fully Wood-Based Transparent Plates with High Strength, Flame Self-Extinction, and Anisotropic Thermal Conduction
Fully Wood-Based Transparent Plates with High Strength, Flame Self-Extinction, and Anisotropic Thermal Conduction
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DOI：
10.1021/acssuschemeng.2c06344
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发表时间：
2023-01
期刊：
影响因子：
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通讯作者：
S. Ishioka;Noriyuki Isobe;Takayuki Hirano;N. Matoba;Shuji Fujisawa;Tsuguyuki Saito
中科院分区：
文献类型：
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作者：
S. Ishioka;Noriyuki Isobe;Takayuki Hirano;N. Matoba;Shuji Fujisawa;Tsuguyuki Saito
玻璃和透明塑料用作建筑物和车辆的采光面材料。然而，这些透明材料的机械性能不如金属、混凝土和纤维增强塑料等其他结构构件，并且对包含它们的整个结构的承载能力没有贡献。在此，我们报告了完全透明且机械强度高的板材（雾度 8%，强度 256 MPa），仅包含具有羧基官能团的木材衍生纤维素纳米纤维 (CNF)。这些板具有毫米厚的层压结构，并通过 CNF 的自粘力结合在一起。它们的强度可与铝合金和玻璃纤维增强塑料等轻质结构材料相媲美，而CNF板甚至更轻。由于CNF的羧酸盐结构，该板具有优异的火焰自熄性能，并进一步表现出面内和面外方向之间的各向异性热传导。还展示了通过羧基的抗衡离子设计克服高吸水率（CNF 材料的一个主要问题）的策略。
Glasses and transparent plastics are used as daylighting face materials in buildings and vehicles. However, these transparent materials are mechanically inferior to other structural members such as metals, concretes, and fiber-reinforced plastics and have no contribution to the load-bearing capacities of whole structures incorporating them. Herein, we report clearly transparent and mechanically strong plate materials (haze 8%, strength 256 MPa) comprising solely wood-derived cellulose nanofibers (CNFs) with carboxy functionality. These plates have a millimeter thick laminated structure and are united by self-adhesive forces of the CNFs. Their strength is comparable to those of light-weight structural materials, such as aluminum alloys and glass fiber-reinforced plastics, while the CNF plates are even lighter. The plates feature excellent flame self-extinguishing properties due to the carboxylate structure of CNFs and further show anisotropic thermal conduction between the in-plane and out-of-plane directions. A strategy for overcoming the high water absorption, a major issue of CNF materials, through the counterion design of carboxy groups is also demonstrated.