Alkane Encapsulation Induces Strain in Small Diameter Single-Wall Carbon Nanotubes

Published: May 04, 2018

Author(s)

Jason K. Streit, Jochen I. Campo, Chad R. Snyder, Ming Zheng, Jeffrey R. Simpson, Angela R. Hight Walker, Jeffrey A. Fagan

Abstract

Encapsulation of linear alkane molecules in the endohedral volumes of small diameter single- wall carbon nanotubes (SWCNTs) is shown to induce diameter dependent strain on the hexagonal lattice of carbon atoms composing the tubular structure. For the smallest diameter nanotubes, such as the (6,5), (9,1), (8,3) and (10,0), encapsulation leads to expansive radial strain. This effect is demonstrated through precision measurements of induced shifts in the energy of the intrinsic optical transitions of single-chirality nanotube populations. The effect on the optical transitions from strain is found to exceed that of the effective dielectric medium change when comparing the same SWCNT population filled with an alkane versus those filled with water. This differs from encapsulation of alkanes into larger diameter nanotubes for which dielectric effects dominate due to the relative sizes of the guest molecules and the SWCNT cavity. For the SWCNT species examined in this work, the interior cavity diameters are smaller than the smallest unstrained cross-section of an alkane molecule. These results imply that SWCNT species-dependent strain is likely to be encountered when encapsulating any molecule into a SWCNT, with particular complexity to be expected for filling by molecules close to the sieving size of the endohedral cavity.
Citation: Journal of Physical Chemistry C
Volume: 122
Issue: 21
Pub Type: Journals

Keywords

nanotube, strain, nanomaterial, SWCNT, SWNT
Created May 04, 2018, Updated November 10, 2018