Characterization of Single- and Multiwalled Carbon Nanotube Composites for Electromagnetic Shielding and Tunable Applications

Conductivity, complex permittivity, and shielding effectiveness (SE) of single- and multiwalled carbon nanotube (SWCNT and MWCNT) composites prepared by ultrasonication dispersion were investigated experimentally. As compared with a manual process, ultrasonication dispersion was able to reduce percolation threshold of the SWCNT composites significantly. Frequency-dependent permittivity of the composite can be well described by the scaling law based on the percolation theory. It is also found that the carbon nanotube (CNT) composites possess large tunable dielectric properties (>;60%) at relatively low bias electrical field (7.5 V/mm), which have potential applications in smart electromagnetic functional structures. SE of the MWCNT composite with 5% CNT and a thickness of 2 mm is about 30 dB at 12 GHz. Therefore, the MWCNT composites are good candidates as flexible shielding materials operating at microwave frequencies.

[1]  Bumsuk Kim,et al.  Electrical properties of single-wall carbon nanotube and epoxy composites , 2003 .

[2]  Meyya Meyyappan,et al.  Carbon Nanotubes: Science and Applications , 2007 .

[3]  L. Kong,et al.  Tunable effective permittivity of carbon nanotube composites , 2008 .

[4]  Eiichi Sano,et al.  Highly strong and conductive carbon nanotube/cellulose composite paper , 2010 .

[5]  M. Dresselhaus,et al.  Physical properties of carbon nanotubes , 1998 .

[6]  S. Iijima.  Helical microtubules of graphitic carbon , 1991, Nature.

[7]  Lain‐Jong Li,et al.  Effect of centrifugation on the purity of single-walled carbon nanotubes from MCM-41 containing cobalt , 2008 .

[8]  K. Banerjee,et al.  Circuit Modeling and Performance Analysis of Multi-Walled Carbon Nanotube Interconnects , 2008, IEEE Transactions on Electron Devices.

[9]  Uttandaraman Sundararaj,et al.  Electromagnetic interference shielding mechanisms of CNT/polymer composites , 2009 .

[10]  Ned Bryant.  EMI shielding effects of carbon nanotubes on traditional EMI plastics , 2010, 2010 IEEE International Symposium on Electromagnetic Compatibility.

[11]  Beng Kang Tay,et al.  Electromagnetic interference shielding effectiveness of carbon-based materials prepared by screen printing , 2009 .

[12]  C. Brosseau.  Generalized effective medium theory and dielectric relaxation in particle-filled polymeric resins , 2002 .

[13]  P. Asbeck,et al.  Enhanced dielectric constants and shielding effectiveness of, uniformly dispersed, functionalized carbon nanotube composites , 2009 .

[14]  Qing Huo Liu,et al.  Electrothermal Characterization of Single-Walled Carbon Nanotube (SWCNT) Interconnect Arrays , 2009, IEEE Transactions on Nanotechnology.

[15]  Gintaras Valušis,et al.  Microwave probing of nanocarbon based epoxy resin composite films: Toward electromagnetic shielding , 2011 .

[16]  Y. Gefen,et al.  Dynamic Scaling near the Percolation Threshold in Thin Au Films , 1984 .

[17]  Hongjun Gao,et al.  The influence of single-walled carbon nanotube structure on the electromagnetic interference shielding efficiency of its epoxy composites , 2007 .

[18]  I. Huynen,et al.  Carbon nanotube composites for broadband microwave absorbing materials , 2006, IEEE Transactions on Microwave Theory and Techniques.

[19]  Hye Jin Lim,et al.  Terahertz electromagnetic interference shielding using single-walled carbon nanotube flexible films , 2008 .

[20]  K. Rozanov,et al.  Frequency dependence of effective permittivity of carbon nanotube composites , 2007 .

[21]  W. Yin,et al.  Electro-thermal characterization of single-walled carbon nanotube (SWCNT) interconnect arrays , 2008, 2008 Electrical Design of Advanced Packaging and Systems Symposium.

[22]  A. Jonscher.  Dielectric relaxation in solids , 1983 .

[23]  D. Kajfez,et al.  Characterization of Multiwalled Carbon Nanotube (MWCNT) Composites in a Waveguide of Square Cross Section , 2008, IEEE Microwave and Wireless Components Letters.

[24]  Q.H. Liu,et al.  Crosstalk Prediction of Single- and Double-Walled Carbon-Nanotube (SWCNT/DWCNT) Bundle Interconnects , 2009, IEEE Transactions on Electron Devices.