Broadband Spectroscopic Thermoacoustic Characterization of Single-Walled Carbon Nanotubes. (15th June 2015)

• Record Type: Journal Article
• Authors: Bauer, Daniel R.; Wang, Xiong; Vollin, Jeff; Xin, Hao; Witte, Russell S.
• Other Names: Sahoo Nanda Gopal Academic Editor.
• Is Part Of: Journal of spectroscopy. Volume 2015(2015)
• Publication Date: 2015-06-15
• Subjects: Spectrum analysis -- Periodicals; 543.505
• DOI: 10.1155/2015/762352
• Languages: English
• ISSNs: 2314-4920

Abstract

Abstract : Carbon nanotubes have attracted interest as contrast agents for biomedical imaging because they strongly absorb electromagnetic radiation in the optical and microwave regions. This study applies thermoacoustic (TA) imaging and spectroscopy to measure the frequency-dependent absorption profile of single-walled carbon nanotubes (SWNT) in the ranges of 2.7–3.1 GHz and 7–9 GHz using two tunable microwave sources. Between 7 and 9 GHz, the peak TA signal for solutions containing semiconducting and metallic SWNTs increased monotonically with a slope of 1.75 AU/GHz (R 2 = 0.95 ) and 2.8 AU/GHz (R 2 = 0.93 ), respectively, relative to a water baseline. However, after compensating for the background signal from water, it was revealed that the TA signal from metallic SWNTs increased exponentially within this frequency band. Results suggest that TA imaging and spectroscopy could be a powerful tool for quantifying the absorption properties of SWNTs and optimizing their performance as contrast agents for imaging or heat sources for thermal therapy.