Soft cutting of single-wall carbon nanotubes by low temperature ultrasonication in a mixture of sulfuric and nitric acids

• Published in: Nanotechnology Vol. 23; no. 49; p. 495714
• Main Authors: Shuba, M V, Paddubskaya, A G, Kuzhir, P P, Maksimenko, S A, Ksenevich, V K, Niaura, G, Seliuta, D, Kasalynas, I, Valusis, G
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 14.12.2012
• Subjects: Cold Temperature; Complex Mixtures - chemistry; Complex Mixtures - radiation effects; Criteria; Crystallization - methods; Cutting; Fourier transforms; Infrared spectroscopy; Materials Testing; Nanotubes, Carbon - chemistry; Nanotubes, Carbon - radiation effects; Nitric acid; Nitric Acid - chemistry; Nitric Acid - radiation effects; Particle Size; Single wall carbon nanotubes; Sonication - methods; Spectra; Sulfuric Acids - chemistry; Sulfuric Acids - radiation effects; Tubes (electronic)
• ISSN: 0957-4484; 1361-6528
• DOI: 10.1088/0957-4484/23/49/495714

To decrease single-wall carbon nanotube (SWCNT) lengths to a value of 100-200 nm, aggressive cutting methods, accompanied by a high loss of starting material, are frequently used. We propose a cutting approach based on low temperature intensive ultrasonication in a mixture of sulfuric and nitric acids. The method is nondestructive with a yield close to 100%. It was applied to cut nanotubes produced in three different ways: gas-phase catalysis, chemical vapor deposition, and electric-arc-discharge methods. Raman and Fourier transform infrared spectroscopy were used to demonstrate that the cut carbon nanotubes have a low extent of sidewall degradation and their electronic properties are close to those of the untreated tubes. It was proposed to use the spectral position of the far-infrared absorption peak as a simple criterion for the estimation of SWCNT length distribution in the samples.