Nano Archive

Controlling nanotube dimensions: Correlation between composition, diameter, and internal energy of single-walled mixed oxide nanotubes

Konduri, Suchitra and Mukherjee, Sanjoy and Nair, Sankar (2007) Controlling nanotube dimensions: Correlation between composition, diameter, and internal energy of single-walled mixed oxide nanotubes. ACS NANO, 1 (5). pp. 393-402.

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Official URL: http://pubs.acs.org/doi/abs/10.1021/nn700104e

Abstract

Control over the diameter of nanotubes is of significance in manipulating their properties, which depend on their dimensions in addition to their structure and composition. This aspect has remained a challenge in both carbon and inorganic nanotubes, since there is no obvious aspect of the formation mechanism that allows facile control over nanotube curvature. Here we develop and analyze a quantitative correlation between the composition, diameter, and internal energy of a class of single-walled mixed oxide aluminosilicogermanate (AlSiGeOH) nanotubes. A series of synthetic AlSiGeOH nanotubes with varying Si/Ge ratio are characterized by Xray photoelectron spectroscopy, vibrational spectroscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction to relate their compositions and diameters. We then study these nanotubes computationally by first parametrizing and validating a suitable interatomic potential model, and then using this potential model to investigate the internal energy of the nanotube as a function of diameter and composition via molecular dynamics simulations. There are minima in the internal energy as a function of diameter which progressively shift to larger nanotube diameters with increasing Ge content. An approximate analytical theory of nanotube diameter control, which contains a small number of physically significant fitted parameters, well describes the computational data by relating the composition and geometry to the strain energy of bending into a nanotube. The predicted composition-dependent shift in the energetically favored diameter follows the experimental trends. We suggest related methods of controlling nanotube energetics and their role in engineering nanotubes of controlled dimensions by liquid-phase chemistry.

Item Type:Article
Uncontrolled Keywords:nanotubes; diameter; composition; energy; molecular dynamics
Subjects:Material Science > Functional and hybrid materials
Material Science > Nanofabrication processes and tools
Physical Science > Nano objects
ID Code:532
Deposited By:IoN
Deposited On:20 Jan 2009 11:20
Last Modified:29 Jan 2009 16:44

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