Bai Chengjie, Jia Siran, Chen Wei, Li Lulu, Zhang Yu, Min Peng, Yu Zhong-Zhen, Zhang Hao-Bin
State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, 100029 Beijing, China.
Key Laboratory of Applied Physical Chemistry of Qinghai Province, Qinghai Minzu University, 810007 Xining, Qinghai, China.
ACS Appl Mater Interfaces. 2025 Feb 19;17(7):11108-11116. doi: 10.1021/acsami.4c21321. Epub 2025 Feb 5.
Miniaturized and wearable electronic products require electromagnetic interference shielding (EMI) materials with sensing functions to cope with complex application situations. Herein, an effective dual-network structure is designed to fabricate two-dimensional transition metal carbides and nitrides/bacterial cellulose-thermoplastic polyurethane (MXene/BC-TPU) foams with intriguing EMI shielding property and piezoelectric sensing ability under both compressive and tensile strains. Anisotropic MXene/BC aerogels, as conductive networks, with impressive conductivity (1912 S m), ultrahigh EMI shielding effectiveness (SE) of 86 dB, and absolute SE up to 63,608 dB cm g can be built by directional freezing. Interpenetrated neuro-like TPU network is embedded into the MXene/BC aerogels by controllable coagulation to provide elasticity. Inheriting the elastic TPU network, the light weight MXene/BC-TPU foams show superb elasticity and remarkable fatigue resistance suffering both compressive and tensile strains with a wide strain range (-80-80%). Meanwhile, benefiting from the separated conductive MXene/BC network and the elastic TPU network, the MXene/BC-TPU foams display an outstanding EMI SE (76 dB) with an EMI SE retention of 86.8% after 5000 compression-release cycles and an EMI SE retention of 69.7% after 100 stretch-release cycles, respectively. Furthermore, the MXene/BC-TPU foams reveal stable resistance signal output as piezoresistive sensors in a wide strain range of -80-80%. The highly conductive, stretchable, and compressible MXene/BC-TPU foams are suitable as EMI shielding and motion monitoring materials for wearable electronics.
小型化和可穿戴电子产品需要具有传感功能的电磁干扰屏蔽（EMI）材料来应对复杂的应用场景。在此，设计了一种有效的双网络结构，以制备具有有趣的EMI屏蔽性能以及在压缩和拉伸应变下的压电感测能力的二维过渡金属碳化物和氮化物/细菌纤维素-热塑性聚氨酯（MXene/BC-TPU）泡沫。通过定向冷冻可以构建各向异性的MXene/BC气凝胶作为导电网络，其具有令人印象深刻的电导率（1912 S/m）、86 dB的超高EMI屏蔽效能（SE）以及高达63608 dB·cm²/g的绝对SE。通过可控凝固将相互贯穿的神经状TPU网络嵌入到MXene/BC气凝胶中以提供弹性。继承弹性TPU网络，轻质MXene/BC-TPU泡沫表现出卓越的弹性和显著的抗疲劳性，在宽应变范围（-80-80%）内承受压缩和拉伸应变。同时，受益于分离的导电MXene/BC网络和弹性TPU网络，MXene/BC-TPU泡沫分别在5000次压缩-释放循环后显示出出色的EMI SE（76 dB），EMI SE保留率为86.8%，在100次拉伸-释放循环后EMI SE保留率为69.7%。此外，MXene/BC-TPU泡沫在-80-80%的宽应变范围内作为压阻式传感器显示出稳定的电阻信号输出。高导电、可拉伸和可压缩MXene/BC-TPU泡沫适合作为可穿戴电子产品的EMI屏蔽和运动监测材料。
