Abstract
Polymer matrix composites filled with carbon nanoparticles are promising materials for many applications, but their properties strongly depend on the particle features, concentration and distribution within the matrix. Here we present a study of the electrical resistivity and the low-frequency voltage fluctuation of composites based on epoxy resin filled with onion-like carbon (OLC) of different sizes (40–250 nm) above the percolation threshold, which should clarify the electrical transport characteristics in these materials. Electrical measurements were performed in the temperature range of 78 to 380 K, and voltage noise analysis was carried out from 10 Hz to 20 kHz. At low temperatures (below 250 K), thermally activated tunneling, variable-range hopping and generation–recombination of charge carriers take place. Above 250 K, the rapid expansion of the matrix with the temperature increases the resistivity, but above ~330 K, the conductivity of the matrix becomes significant. Quasi one-dimensional electrical transport is observed in composites with the smallest particles (40 nm), while in composites with the largest particles (220–250 nm), the dimensionality of the electrical transport is higher. The temperature dependence of the electrical conductivity of composites with smaller particles is more sensitive to matrix expansion.
Highlights
Published: 24 March 2021Carbon is a chemical element with a wide variety of structures, leading to a broad range of physical properties
By analyzing the resistance characteristics of the investigated materials, one can note different dependencies of the measured parameters, some of them being specific to these composites only, whereas others are typical of the most polymer composites filled with carbon nanoparticles
The electrical resistivity and low-frequency voltage noise characteristics of composite materials based on an epoxy matrix filled with onion-like carbon nanoparticles were investigated
Summary
Carbon is a chemical element with a wide variety of structures, leading to a broad range of physical properties. These remarkable characteristics are attracting increasing attention, and have led to numerous studies of carbon-containing materials [1,2,3]. Fullerenes are one of the forms of carbon that have stimulated study of these materials and similar structures, and have practically formed a new branch in themselves in materials science and nanotechnology. The large multi-shelled carbon fullerenes are called onion-like carbons (OLCs) They always have structural defects and high electrical conductivity, like carbon nanotubes [7]. They are often used for various electronic applications, in sensors and for electromagnetic shielding [8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
