TY - JOUR
T1 - Large-scale synthesis, characterization and microwave absorption properties of carbon nanotubes of different helicities
AU - Qi, Xiaosi
AU - Yang, Yi
AU - Zhong, Wei
AU - Deng, Yu
AU - Au, Chaktong
AU - Du, Youwei
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China (Grant no. 10674059), the National High Technology Research and Development Program of China (Grant no. 2007AA021805), and the National Key Project for Basic Research (Grant no. 2005CB623605), People's Republic of China.
PY - 2009/10
Y1 - 2009/10
N2 - 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.
AB - 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.
KW - Carbon nanotubes
KW - Complex permeability
KW - Complex permittivity
KW - Reflection loss
UR - http://www.scopus.com/inward/record.url?scp=70349478639&partnerID=8YFLogxK
U2 - 10.1016/j.jssc.2009.07.036
DO - 10.1016/j.jssc.2009.07.036
M3 - Journal article
AN - SCOPUS:70349478639
SN - 0022-4596
VL - 182
SP - 2691
EP - 2697
JO - Journal of Solid State Chemistry
JF - Journal of Solid State Chemistry
IS - 10
ER -