With the miniaturization, intelligence, and complication of the use environment of electronic devices, ordinary metal conductor materials can no longer meet the development needs of electronic devices. Research and development of next-generation conductor materials has become one of the goals of researchers. Carbon nanotubes are the most promising next-generation conductor materials because of their good electrical conductivity, corrosion resistance, low density, and mechanical strength. However, due to the weak van der Waals force and obvious electron and phonon scattering between the carbon nanotubes, when the carbon nanotubes form a macrostructure (such as carbon nanotube fibers and thin films), there will be great loss of electrical and mechanical properties. At present, researchers mainly improve the electrical conductivity by depositing metal on the surface of the carbon nanotube macroscopic body, but this method causes the composite material to reduce the strength.
In response to this problem, the group of Professor Meng Xiangkang of the School of Modern Engineering and Applied Sciences of Nanjing University deposited an ultra-thin aluminum-copper composite film on the surface of carbon nanotube fibers by magnetron sputtering process, and annealed and densified the metal elements to diffuse. The formation of nanoparticles into the carbon nanotube fibers achieves the purpose of reducing the contact resistance between the carbon nanotubes, and significantly improves the electrical conductivity of the composite. When stretched and deformed, the particles distributed between the carbon nanotubes act as a "bridge", and the particles distributed on the top will act as a "pinning". The two types of nanoparticles increase the sliding resistance between the carbon nanotubes. , Thereby significantly improving the tensile strength and elastic modulus of the composite material. This structure achieves a simultaneous increase in the conductivity and strength of carbon nanotube metal composites, and obtains carbon nanometers with ultra-high strength (6.6 GPa), elastic modulus (500 GPa), and electrical conductivity (1.8 * 107 S / m). Tube aluminum-copper nanocomposite.
Carbon Nanotube / Aluminum-Copper Composite Fiber Morphology and Microstructure, Electrical Conductivity vs. Intensity Relationship, and Uniaxial Tension Enhancement Mechanism
This work provided new ideas for the design of carbon nanotube composite materials and promoted the development of carbon nanotube metal composite material preparation technology. The work, entitled "Ultrastrong and Stiff Carbon Nanotube / Aluminum-Copper Nanocomposite via Enhancing Friction between Carbon Nanotubes", has been published in Nano Letters, an authoritative journal in the nanometer field (DOI: 10.1021 / acs.nanolett.9b02332).