Carbon-Coated Nickel Nanoparticles: Effect on the Magnetic and Electric Properties of Composite Materials

Abstract

Nickel nanoparticles coated with few layers of carbon have been embedded into the polydimethylsiloxane (PDMS) matrix in concentrations up to 11 vol %. Dielectric and magnetic properties of composite materials have been studied in wide frequency (20 Hz-1 MHz) and temperature (130-430 K) ranges. It was demonstrated that the temperature behavior of dielectric properties is determined by glass transitions in the PDSM matrix below 200 K and the Maxwell-Wagner relaxation above room temperature. The possibility of using fabricated composites on the basis of the PDMS matrix for producing a wide range of passive electromagnetic components, such as frequency-selective filters, wide-band detectors/sensors of a bolometric type, and even electromagnetic "black holes" is also discussed.

Improvements of Arboblend V2 Nature Characteristics through Depositing Thin Ceramic Layers

“…In addition, another area targeted by coating researchers is related to composites based on polymer matrices with the inclusion of magnetic nano-sized particles: Polydimethylsiloxane (PDMS) coated with different concentrations of nanosized Ni@C core-shell [18]; Ni-silicone elastomagnetic composites [19]; polyacrylamide-based hydrogels coated with Ni ferrite [20]; polyetherurethane (TFX) and a biodegradable multiblock copolymer (PDC) with poly(p-dioxanone) as hard segment and poly(ε-caprolactone) as soft segment were investigated as matrix component, coated with iron oxide particles [21]; and oligo(εcaprolactone)dimethacrylate/butyl acrylate, coated with Fe 3 O 4 [22]; carbon-fiber-epoxy composites coated with two thermal ceramic particles (lass flakes and aluminum titanate) in order to create a thermal barrier for the substrate [23]. The interest of researchers was focused mainly on elastomagnetic effects [19] and the wide prospects of applications as follows: Ni ferrite with a highly organized structure as humidity sensors [20]; magnetic nanoparticles for practical applications which involve sensors and biosensors [24]; magnetoresistive sensors for applications where the ultimate field detection limits are required or as readers in hard disk drives [25]; Mg substitution on Ni-ferrite ceramics with applications in biomedicine, gas detection, heterogeneous catalysis, adsorption, etc.…”

Dielectric Relaxation Spectroscopy and Synergy Effects in Epoxy/MWCNT/Ni@C Composites

“…Nickel (Ni) nanosized particles and carbon-coated Ni nanoparticles (Ni@C) have superparamagnetic or ferromagnetic features, which, due to the presence of magnetic losses [ 18 , 19 ], make them promising for the design of microwave absorbing devices. The thermal behaviour of broadband dielectric and magnetic properties has been studied for the composites made of polymer filled with Ni@C concentrations below the percolation threshold [ 20 ]. However, the dielectric properties of composites with Ni@C content above the percolation threshold, the electrical percolation in these composites, and hybrid composites combining Ni@C and MWCNTs fillers have not been studied yet.…”

Enhanced dielectric properties of epoxy-based photoresist nanocomposites using carbon-coated nickel nanoparticles for high voltage integrated capacitors

“…Achieving a homogeneous dispersion of Ni nanoparticles in a polymeric matrix is not straightforward mainly because of their magnetism. Therefore, controlling the homogeneity of the dispersion still represents a significant challenge (13)(14)(15)(16). In order to achieve this, we present a detailed study of sonodispersion protocols of nanoparticles in solution aiming to minimize particle aggregation.…”