Low temperature assembly of fullerene arrays in single-walled carbon nanotubes using supercritical fluids

Abstract

Molecules assembled inside nanotubes to form 1D arrays exhibit functional properties different to the bulk crystal and have been proposed for many applications ranging from catalysis to quantum computing. We have discovered that single-walled carbon nanotubes can be efficiently filled with fullerenes in supercritical fluids at temperatures as low as 30-50 uC. Despite the low solubility of fullerenes in supercritical fluids, the nanotube filling was particularly effective in supercritical carbon dioxide producing C n @SWNT structures in 70% yield at 50 uC. This method was also applied for functionalized and endohedral fullerenes and allows insertion of thermally unstable molecules which would be impossible to insert in nanotubes using standard techniques. We discuss the advantages of using supercritical fluids as compared to conventional solvents and propose mechanisms for fullerene encapsulation at low temperatures.

Towards a fullerene-based quantum computer

“…This technology is applicable to a wide variety of fullerenes, including fullerenes with spacer groups and groups that hydrogen bonds [62,63,64]. Extending this approach, we can make novel covalently bonded structures by inserting highly reactive fullerene epoxide, C 60 O, into SWNTs using supercritical carbon dioxide and then heating the resulting peapods to form a (C 60 O) n polymer.…”

Multiferroic nanocomposite fabrication via liquid phase using anodic alumina template

“…In order to increase the remanent polarization, complete filling of CFO with BTO will be crucial, which also enables a poling process at huge poling voltage. As for achieving the absolute filling of nanotubes, supercritical fluid impregnation [24], vacuum impregnation [25,26], electrophoretic deposition of BTO nanoparticles [27], and the combination of them will work; thus, they are currently under investigation in our research group. On the other hand, BTO nanoparticle assembly has shown enhanced dielectric properties compared to bulk BTO [28].…”

Encapsulating C59N azafullerenes inside single‐wall carbon nanotubes

“…We recently found that chemical reactions are not restricted to fullerenes but organic solvents such as benzene or toluene can also participate [6]. The breakthrough to further explore the in-the-tube chemistry was the discovery of encapsulating fullerenes or fullerene derivatives at ambient temperatures [7,8,9,10,11]. Conventional peapod synthesis involves heating the sample above 400-500 • C [12,13], which most fullerene derivatives do not tolerate.…”