Effect of the preparation methods on electrical properties of epoxy resin/carbon nanofiber composites

The effect of preparation methods on the electrical properties of epoxy resin/carbon nanofiber (ER/CNF) composites has been investigated. The conductivity, permittivity, and loss tangent of composite materials has been measured in the frequency range of 0. 09 Hz-1 MHz in the region below and above the percolation threshold. Three main preparation methods have been used: mechanical mixing, ultrasonication in ER and a solvent. The electrical properties of composites that were prepared using ultrasonication in a solvent have been determined in a wide range of filler concentrations 0 < p < 45 wt %. It was shown that the effect of the preparation methods on the composite properties varies depending on whether the filler concentration is above or below the percolation threshold. © 2012 Pleiades Publishing, Ltd.