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Open AccessArticle

Percolative Composites with Carbon Nanohorns: Low-Frequency and Ultra-High Frequency Response

1
Nikolaev Institute of Inorganic Chemistry SB RAS, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk, Russia
2
Laboratory for Terahertz Research, Tomsk State University, 36 Lenin Ave., 634050 Tomsk, Russia
*
Author to whom correspondence should be addressed.
Materials 2019, 12(11), 1848; https://doi.org/10.3390/ma12111848
Received: 12 April 2019 / Revised: 20 May 2019 / Accepted: 3 June 2019 / Published: 6 June 2019
(This article belongs to the Special Issue Carbon Based Functional Microwave Shields)
We systematically studied the electromagnetic properties of carbon nanohorns (CNHs) and polystyrene composites filled with CNHs in static regime, low frequency and microwave regions. CNHs were synthesized using the direct current arc-discharge method using solid graphite rods and graphite rods filled by melamine mixed with graphite powder. Transmission electron microscopy and thermo-gravimetric analysis showed that CNH agglomerates are the main product, while the addition of melamine promotes the formation of graphite balls. Graphitic contamination causes the internal leakage of inter-agglomerate capacity, lowering the permittivity and enhancing the conductivity of composites. The permittivity of CNH/polystyrene composites increases with the filler fraction, and near the dielectric threshold electromagnetic characteristics of the composites exhibit critical behaviour. Our results suggest that CNHs with relatively high values of permittivity and contact resistance could be used as high-k materials. View Full-Text
Keywords: carbon nanohorns; DC conductivity; AC conductivity; permittivity; electromagnetic shielding carbon nanohorns; DC conductivity; AC conductivity; permittivity; electromagnetic shielding
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Sedelnikova, O.V.; Baskakova, K.I.; Gusel’nikov, A.V.; Plyusnin, P.E.; Bulusheva, L.G.; Okotrub, A.V. Percolative Composites with Carbon Nanohorns: Low-Frequency and Ultra-High Frequency Response. Materials 2019, 12, 1848.

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