Low‐temperature encapsulation of coronene in carbon nanotubes

Abstract

Coronene was encapsulated in single-walled carbon nanotubes (SWNT) by vapor-phase filling at high (450 8C) and low (385 8C) temperature and by nanoextraction from supercritical carbon dioxide. The presence of coronene inside the tubes was demonstrated indirectly via the formation of double-walled nanotubes (DWNT). To this end several subsequent annealing steps were applied and monitored by Raman spectroscopy. Our results show that the encapsulation is successful with all three methods. However, high-temperature vapor filling produces adsorbed dicoronylene, the dimerized form of coronene, as a side reaction. In order to avoid dicoronylene contamination, we suggest to use low-temperature methods for the production of coronene-filled carbon nanotubes.Coronene (top) and dicoronylene (bottom) molecules.

Coronene Encapsulation in Single‐Walled Carbon Nanotubes: Stacked Columns, Peapods, and Nanoribbons

“…[38] The geometrical effect of argon for the encapsulation of molecules into SWNTs demonstrated in our study is likely to be found for other gases as well and may possibly lead to the synthesis of new materials by using reactions of molecules in a space not only confined by the walls of the nanotube but also by the pressure of various gases. However, our experiments revealed that filling nanotubes under an atmosphere of argon gas provides rather different conditions for encapsulation of planar molecules and results in different kinds of products if the molecules react with each other inside the nanotubes.…”

A Review of Double-Walled and Triple-Walled Carbon Nanotube Synthesis and Applications

“…Pea pod-derived DWNTs and TWNTs have specific advantages and disadvantages over the DWNTs and TWNTs grown by the arc-discharge method and the CVD method [104,120,130,131,[134][135][136][137][138][139][140][141][142]150]. One advantage is that the method of growing the multi-walled structures by thermally-treating pea pods makes it possible to obtain high-purity CNTs without contaminants, such as metallic impurities.…”

“…This happens because the electronic structure of the constituent inner tubes is predominantly determined by the outer tubes, as well as by the high temperature observed during the thermal treatment. It is very interesting to note that the interlayer spacing in pea pod-derived structures strongly depends on the high temperatures achieved during the thermal treatment [104,120,130,131,[134][135][136][137][138][139][140][141][142]150].…”

“…Eventually, it will be possible to synthesize chirality-specific DWNTs and TWNTs using chirality-specific SWNTs as host materials and optimized thermal treatment conditions (e.g., temperature and environment of the growth process) [104,120,130,131,[134][135][136][137][138][139][140][141][142]150]. However, the pea pod-derived method presents the following disadvantages: (1) it suffers from the limited filling ratio of fullerenes inside SWNTs, which leads to the formation of very short or disconnected inner tubes; (2) it has limited production capacity; (3) it relies upon high-cost ultra-crystalline arc-discharge-derived SWNTs (in the case of the DWNT synthesis) to serve as host materials; and (4) the method also depends on high-cost material processing techniques, as for example, the technique used to encapsulate the fullerene molecules and the high temperatures required during the thermal treatment [104,120,130,131,[134][135][136][137][138][139][140][141][142]150]. This is likely why, intrinsically, the CVD method has been largely used to produce CNTs at an industrial scale.…”

Behavior of Coronene in the Mixed Langmuir-Blodgett (LB) Films of Two Different Matrixes on Water and Solid Surfaces

“…Interest in an important PAH, namely coronene, also known as superbenzene stems from the fact that it has an intense structured fluorescence in the green region of visible spectrum that makes it a good candidate for excellent fluorescent molecular probe as revealed in several studies (10,11).Due to its high molecular symmetry (D 6h ), coronene has been favorite for spectroscopic studies. Coronene was encapsulated in the single walled carbon nanotubes for the production of coronene filled carbon nanotube (12). A few members of coronene family were investigated in supramolecular electronics and its one derivative was found to form excellent carbon nanotube with interesting electrical properties (13).…”