Ultralight Cellulose Porous Composites with Manipulated Porous Structure and Carbon Nanotube Distribution for Promising Electromagnetic Interference Shielding
Ultralight Cellulose Porous Composites with Manipulated Porous Structure and Carbon Nanotube Distribution for Promising Electromagnetic Interference Shielding
复制标题
具有可控多孔结构和碳纳米管分布的超轻纤维素多孔复合材料有望实现电磁干扰屏蔽
DOI：
10.1021/acsami.8b14738
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发表时间：
2018
影响因子：
9.5
通讯作者：
Li Zhong-Ming
中科院分区：
文献类型：
--
作者：
Zhang Liang-Qing;Yang Shu-Gui;Li Lei;Yang Biao;Huang Hua-Dong;Yan Ding-Xiang;Zhong Gan-Ji;Xu Ling;Li Zhong-Ming
基于生物质的轻质导电高分子复合材料在电磁干扰屏蔽领域具有广阔的应用前景。在本文中，定制多孔微结构和调节碳纳米管（CNT）在纤维素复合材料中的分布是实现高效EMI屏蔽性能的尝试，同时具有期望的机械性能和低密度。具体而言，通过冰模板冷冻干燥法制备定向多孔结构，同时调控碳纳米管修饰在纤维素基体内部（碳纳米管基体/纤维素多孔复合材料）或直接结合在纤维素细胞壁上（碳纳米管界面/纤维素多孔复合材料）。结果发现，由于碳纳米管的细胞壁上的优先分布，CNT界面/纤维素多孔复合材料具有非常高的电导率为38.9 S m-1与一个非常低的渗流阈值为0.0083体积%的CNT-基质/纤维素多孔复合材料。因此，在CNT界面/纤维素多孔复合材料中，在厚度为2.5 mm的情况下仅用0.51体积% CNT就实现了40 dB的屏蔽效能，这归因于有效的多次反射和伴随的吸收，以及促进的导电性和更好限定的多孔结构。此外，CNT-界面/纤维素多孔复合材料显示出上级机械性能，比模量为279 MPa g-1cm 3。目前工作背后的价值是为制造环境友好的高性能EMI屏蔽材料铺平了有效的道路，以实际推动纤维素的许多先进应用。
Lightweight conductive polymer composites based on biomass could be a promising candidate for electromagnetic interference (EMI) shielding application. Herein, tailoring porous microstructure and regulating the distribution of carbon nanotubes (CNTs) in cellulose composites are attempts to achieve highly efficient EMI shielding properties accompanying desired mechanical property and low density. Specifically, aligned porous structure is fabricated by ice-template freeze-drying method; meanwhile, CNT is regulated to decorate inside the cellulose matrix (CNT-matrix/cellulose porous composites) or to directly bind over the cellulose cell walls (CNT-interface/cellulose porous composites). It is found that, owing to the preferential distribution of CNT on the cell walls, the CNT-interface/cellulose porous composites possess a very high electrical conductivity of 38.9 S m–1with an extremely low percolation threshold of 0.0083 vol % with regard to CNT-matrix/cellulose porous composites. Therefore, a shielding effectiveness of 40 dB with merely 0.51 vol % CNT under a thickness of 2.5 mm is achieved in CNT-interface/cellulose porous composites, which is attributed to efficient multiple reflections and the accompanying absorption with promoted conductivity and better-defined porous structure. More laudably, the CNT-interface/cellulose porous composites reveal a superior mechanical property with a specific modulus of 279 MPa g–1cm3. The value behind the current work is to pave an effective way to fabricate environmentally benign, high-performance EMI shielding materials to practically boost numerous advanced applications of cellulose.