Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Chemistry, Beihang University, 100191 Beijing, China.
School of Physics, Beihang University, 100191 Beijing, China.
Proc Natl Acad Sci U S A. 2020 Nov 3;117(44):27154-27161. doi: 10.1073/pnas.2009432117. Epub 2020 Oct 21.
Titanium carbide (TiCT) MXene has great potential for use in aerospace and flexible electronics due to its excellent electrical conductivity and mechanical properties. However, the assembly of MXene nanosheets into macroscopic high-performance nanocomposites is challenging, limiting MXene's practical applications. Here we describe our work fabricating strong and highly conductive MXene sheets through sequential bridging of hydrogen and ionic bonding. The ionic bonding agent decreases interplanar spacing and increases MXene nanosheet alignment, while the hydrogen bonding agent increases interplanar spacing and decreases MXene nanosheet alignment. Successive application of hydrogen and ionic bonding agents optimizes toughness, tensile strength, oxidation resistance in a humid environment, and resistance to sonication disintegration and mechanical abuse. The tensile strength of these MXene sheets reaches up to 436 MPa. The electrical conductivity and weight-normalized shielding efficiency are also as high as 2,988 S/cm and 58,929 dB∙cm/g, respectively. The toughening and strengthening mechanisms are revealed by molecular-dynamics simulations. Our sequential bridging strategy opens an avenue for the assembly of other high-performance MXene nanocomposites.
碳化钛（TiCT）MXene 因其优异的导电性和机械性能，在航空航天和柔性电子领域有很大的应用潜力。然而，将 MXene 纳米片组装成宏观高性能纳米复合材料具有挑战性，限制了 MXene 的实际应用。在这里，我们描述了通过顺序桥接氢键和离子键来制备强韧和高导电性 MXene 片的工作。离子键合剂减小了层间距并增加了 MXene 纳米片的取向，而氢键合剂增加了层间距并减小了 MXene 纳米片的取向。氢键和离子键合剂的连续应用优化了韧性、拉伸强度、在潮湿环境中的抗氧化性以及抗超声分散和机械滥用的能力。这些 MXene 片的拉伸强度高达 436 MPa。电导率和重量归一化屏蔽效率也高达 2988 S/cm 和 58929 dB•cm/g。通过分子动力学模拟揭示了增韧和增强机制。我们的顺序桥接策略为组装其他高性能 MXene 纳米复合材料开辟了一条途径。
