Single-Walled Carbon Nanotube/Copper Core–Shell Fibers with a High Specific Electrical Conductivity

Abstract

Carbon nanotube (CNT)/Cu core−shell fibers are a promising material for lightweight conductors due to their higher conductivity than pure CNT fibers and lower density than traditional Cu wires. However, the electrical properties of the hybrid fiber have been unsatisfactory, mainly because of the weak CNT−Cu interfacial interaction. Here we report the fabrication of a single-walled CNT (SWCNT)/Cu core−shell fiber that outperforms commercial Cu wires in terms of specific electrical conductivity and current carrying capacity. A dense and uniform Cu shell was coated on the surface of wet-spun SWCNT fibers using a combination of magnetron sputtering and electrochemical deposition. Our SWCNT/Cu core−shell fibers had an ultrahigh specific electrical conductivity of (1.01 ± 0.04) × 10 4 S m 2 kg −1 , 56% higher than Cu. Experimental and simulation results show that oxygen-containing functional groups on the surface of a wetspun SWCNT fiber interact with the sputtered Cu atoms to produce strong bonding. Our hybrid fiber preserved its integrity and conductivity well after more than 5000 bending cycles. Furthermore, the current carrying capacity of the coaxial fiber reached 3.14 × 10 5 A cm −2 , three times that of commercial Cu wires.

Preliminary fabrication and analysis of a novel porous Cu-CNT composite for photothermal applications

“…This particular combination is excellent in applications requiring efficient heat management, like heat sinks and friction control [22,23], or photothermal power plants, where it serves as a crucial thermal interface material. Furthermore, the Cu-CNT combination can effectively enhance the current-carrying capacity of the composite by up to 100 times, thermal conductivity by nearly 180%, and significantly reduce the weight per unit volume of the mixture [24,25]. This study employs a newly developed method devised by our research team to produce porous Cu-CNT samples.…”

Computed Gyration Tensors of Knotted Chiral and Achiral Topological Stereoisomers of C60 Cyclocarbons

“…[18][19][20] A knot recently has been tied in singlewalled carbon nanotubes, albeit it is on the micron scale, and not suited for atomistic calculations. [21] Herein, we compare the computed gyration tensors of a pair of isomers whose molecular graphs are topologically equivalent to the simplest non-trivial knot, the chiral trefoil 3 1 (right-handed), of approximate symmetry D 3 , and the simplest achiral knot, the figure eight, 4 1 , of approximate symmetry S 4 (Figure 2). [22] The compounds are numbered as 3 1 and 4 1 according to Alexander and Briggs where 3 1 means the 1 st (by convention) knot with 3 crossings in its minimum crossing presentation.…”

Strong Connection of Single-Wall Carbon Nanotube Fibers with a Copper Substrate Using an Intermediate Nickel Layer

“…The rapid development of wearable electronics, the smart grid, an intelligent society, and deep-sea and deep-space exploration has produced an increasing need for advanced fiber materials. − Carbon nanotube fibers (CNTFs) are a very competitive candidate which are expected to find a wide range of applications including aerospace, railway, and automotive engineering, due to their low-density, high thermal and electrical conductivities, resistance to corrosion and erosion, and excellent mechanical performance. − However, the practical use of CNTFs has been severely restricted due to a major difficulty in joining CNTFs to metals. Especially, joining CNTFs to copper is an immediate problem because of the universal use of Cu as conducting components in electronic and electrical systems.…”