Document Type

Journal Article

Department/Unit

Department of Chemistry

Title

Large-scale synthesis, characterization and microwave absorption properties of carbon nanotubes of different helicities

Language

English

Abstract

Carbon nanotubes of high helicity (H-HCNTs, Sample A) have been synthesized in large-scale by pyrolysis of acetylene at 450 °C over Fe nanoparticles derived from coprecipitation/hydrogen reduction method. With controlled introduction of hydrogen during acetylene pyrolysis, CNTs of low helicity (L-HCNTs, Sample B) and worm-like CNTs (Sample C) were obtained in large quantities. The yields of the CNTs products are high, especially that of H-HCNTs (ca. 7474%). The complex permittivity and permeability of Composites A, B, and C that contain Samples A, B and C (30 wt%) were measured in the 2-18 GHz frequency range. Good absorption of electromagnetic wave (reflection loss<-20 dB) was observed in the 7.18-10.68 and 7.5-10.7 GHz range over Composites B and C (2.0-3.0 mm thickness), respectively. Thus, through the suggested route, CNTs can be produced easily and selectively in large quantities. The lightweight materials can be utilized for microwave absorption. © 2009 Elsevier Inc. All rights reserved.

Keywords

Carbon nanotubes, Complex permeability, Complex permittivity, Reflection loss

Publication Date

2009

Source Publication Title

Journal of Solid State Chemistry

Volume

182

Issue

10

Start Page

2691

End Page

2697

Publisher

Elsevier

DOI

10.1016/j.jssc.2009.07.036

Link to Publisher's Edition

http://dx.doi.org/10.1016/j.jssc.2009.07.036

ISSN (print)

00224596

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