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

Autor: Olga V. Sedelnikova, Kseniya I. Baskakova, Artem V. Gusel’nikov, Pavel E. Plyusnin, Lyubov G. Bulusheva, Alexander V. Okotrub
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Materials, Vol 12, Iss 11, p 1848 (2019)
Druh dokumentu: article
ISSN: 1996-1944
12111848
DOI: 10.3390/ma12111848
Popis: 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.
Databáze: Directory of Open Access Journals
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