Study on electromagnetic properties and microwave absorbing characteristics of carbon nanofibers

摘要

In this study,carbon nanofibers (CNFs) with the typical diameter ranging from 100~300nm were prepared via polymer blended wet-spinning method and subsequent thermal treatment.The complex permittivity (ε'-jε''),complex permeability (μ'-jμ'') and microwave absorption properties of carbon nanofibers/epoxy composites have been studied in Xband frequency range (8.2-12.4 GHz) using a HP8722ES network system.ε',ε'',μ' and μ'' are found to increase with increased CNF contents.Measured values of these parameters were used to determine the reflection loss at various sample thicknesses,based on a model of a single-layered plane wave absorber backed by a perfect conductor.The composite with 8wt% CNFs has shown a maximum reflection loss of -34dB at 10.5GHz with the -10dB bandwidth over the extended frequency range of 8.8-12.4GHz which covers almost the whole X-band at a thickness of 2.1mm.