Nanobuds promote heat welding of carbon nanotubes at experimentally-relevant temperatures

Abstract

Nanobuds promote heat welding of carbon nanotubes at experimentally-relevant temperatures.

Effects of nanobuds and heat welded nanobuds chains on mechanical behavior of carbon nanotubes

“…However, it should be different for nanobuds with attaching configuration where both the structure of fullerene and carbon nanotube in one nanobud are defect-free [28]. We have reported the effect of bombardment formed nanobuds with attaching configuration on the tensile strength of carbon nanotube [14], however the bombardment formed nanobuds with attaching configuration is not so typical because their distortion and stress concentration in the connection area between C 60 and the SWCNT by collision are generally more serious than those nanobuds synthesized by chemical functionalization or formed by applying pressure [27]. More importantly, how the nanobuds with attaching configuration affect the tensile strength of carbon nanotubes is not fully understood at present, and how multiple attached C 60 molecules or nanobuds chain with attaching configuration will affect the tensile strength of carbon nanotubes still need to be investigated.…”

“…The simulation method of the nanobuds formation by applying pressure has been described in details in our previous works [27] and will be employed in this work as well. In the simulations, the initial distance between C 60 and single-walled CNT (SWCNT) is set to a certain value ranging from 0.8 to 1.6 Å which is less than the van der Waals distance of 3.4 Å, and thus the effect is similar to applying a pressure to make the C 60 and CNT close.…”

“…8. Initial configuration and a typical tensile state of CNT (10, 10) with or without a single vacancy defect with two nanobuds chains molecules attached to the CNTs at elevated temperature, thus forming chains of C 60 fullerenes [27].…”

“…The details of simulation method of heat welding for CNTs or C 60 chains has been described in our previous works [27,[35][36][37] and will be employed here as well. Here first by the contact method [27], the C 60 fullerenes are attached in a straight line along the upper and lower surface of the CNT, and then ends of the (10, 10) SWNTs (1.356 nm diameter) with the formed nanobuds are constrained, and the system excluding the constrained regions of CNT is heated from 300 K to a maximum temperature of 1500 K in 2 ns. The temperature is kept at the maximum temperature for 10 ns with a fixed timestep of 0.5 fs using the Nosé-Hoover thermostat.…”

“…In recent years, the properties of nanobuds have been extensively studied, including their structures [15][16][17][18], electronic properties [19][20], chemical properties [21][22][23][24], thermal transport properties [25], magnetic properties [26] and mechanical property [14,19]. Our recent study also showed that nanobuds can promote heat welding of carbon nanotubes and SWCNTs independent of their diameters can be welded together via nanobuds even at a temperature below 1500 K [27].…”