October 16, 2018
Researchers at the State University of Campinas in Brazil have recently produced nanodiamonds and other nanocarbon materials by targeted high-speed crushing; this technology is expected to solve the structural damage of objects caused by high-speed impact.
Nano-diamonds and other nano-carbon materials formed when carbon nano-balls are launched at extremely high speeds
Experiments carried out ballistic crushing of carbon nanotubes under different speed conditions to obtain nanodiamonds; research found that this high-energy impact can cause the atomic bonds in the carbon nanotubes to break and recombine, thereby forming a new structure. The co-author of the paper Sehmus Ozden introduced: Understanding how the atomic bonds of carbon nanotubes are reorganized can help us use this recombination method to develop ultra-light materials
This technology can be used in spacecraft and satellite materials to effectively resist the collision of high-speed projectiles. The research results were published in the Journal of the American Chemical Society.
High-speed projectiles such as meteorites and orbital debris can cause devastating damage to spacecraft and satellites. The use of lightweight and flexible materials can greatly reduce the damage caused by collisions. Carbon nanotubes are the best choice for the development of this new material.
The staff loaded the multi-layer carbon nanotubes into the spherical bullets, and then used the second-level light gas cannon to shoot at the aluminum target; the shooting impact under three different speed conditions was analyzed.
In the low-velocity impact test of 3.9 km/s, the structure of the carbon nanotubes remained unchanged; when the speed was increased to 5.2 km/s, some of the carbon nanotube structure remained unchanged; when the speed was increased to 6.9 km/s, the structure of carbon nanotubes remained unchanged. The structure of the carbon nanotubes is basically crushed, and the original structure has changed; at this time, most of the carbon nanotubes are split into strips.
Collaborator Chandra Sekhar Tiwary discovered that the few surviving carbon nanotubes and nanoribbons were combined, as shown in the TEM image below.
The TEM image of the nanodiamond formed in the carbon nanotube shot at high speed, the embedded image is the diffraction image of the nanostructure
Tiwary said that previous research has found that carbon nanotubes can form graphene ribbons under extremely high-speed conditions; we have always hoped to obtain a carbon nano-bonded structure, but at the same time, it is indeed surprising that the formation of nanodiamonds can be found. According to Ajayan's analysis, the mutual orientation of nanotubes, the targeting relationship between nanotubes and aluminum, as well as the number of layers of nanotubes and the emission speed all have an important influence on the formation of the final material structure.
Leonardo Machado, a team collaborator, commented: This research has opened up a new way for high-speed impact technology to manufacture nanomaterials, and it may play a pivotal role in the application of materials for spacecraft and satellites in the future.