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Building a space elevator, the cable between Earth and orbiting satellite which provides easy access to space may be unlikely to happen. Based on a recent study, a cable would require a tensile strength of 50 GPa, which means CNTs will not be enough.

The carbon nanotubes or CNTs are known to be the future material that can bind a very strong but light applications such computer components.  However, it appears that one out-of-place atom can cut the strength by more than half. Which means that one of the more unconventional applications for CNT fibers, the sci-fi elevator, may  never happen. The strength of the tubes is the effect of their atomic structure, having walls from one layer of carbon atoms chained in hexagonal grid, according to Spectrum.

Based on studies, a single CNT may have 100 gigapascals of tensile strength, which makes it among the durable materials, yet any attempt to spin several nanotubes into the practical-large scale fiber have created ropes with the strength of 1 GPa. Feng Ding from the Hongkong University, along with some colleagues, simulated CNTs with a single atom out of place, thereby turning both hexagons into into a heptagon and a pentagon, and then making a kink in the tube. The team discovered that a simple change can cut the strength of a CNT to 40 GPa, noting that that effect will become more severe if the number of misaligned atoms will be increased.

The simulations indicate that the kink works as the tube's weak point that quickly snaps the usually strong carbon to carbon bonds. When this happens, the bonds in adjoining hexagons will also break, therefore, unzipping the tube entirely. There is a similar effect when CNTs spun together into fibers: when CNT breaks, the force on the others rises, which eventually leads to fracturing them in the sequence.

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