A quantitative method to evaluate the degree of dispersion of single-walled carbon nanotubes (SWCNTs), produced by the high-pressure carbon monoxide process, was developed using Raman spectroscopy and atomic force microscopy (AFM). Nanotubes were dispersed in sodium dodecyl sulfate aqueous solution at seven different dispersion states by controlling ultra-sonication and centrifugation parameters. It is known that the intensity of a Raman peak at 267 cm-1, at the excitation wavelength of 785 nm, is qualitatively proportional to the degree of aggregation. Here, we provide a quantitative calibration technique which involves single-layer spin-deposition of SWCNTs on mica substrates and z-scan analysis of AFM. The trend of the height measurements of AFM precisely matched that of the Raman peak at 267 cm-1. Therefore, this approach can be used to quantitatively characterize the dispersion state of SWCNTs.
Bibliographical noteFunding Information:
This work was supported by a Grant No. R01-2006-000-10065-0 (2008) from the Basic Research Program of the Korea Science and Engineering Foundation and by a Grant from Center for Nanoscale Mechatronics and Manufacturing, one of the 21st Century Frontier Research Programs supported by Ministry of Science and Technology, Korea.
ASJC Scopus subject areas
- General Chemistry
- General Materials Science