Effect of oxidant concentration on the microwave properties of oxidized carbon fibers

Abstract

Here, we report how the oxidation of carbon fibers (CFs) with H2O2 and HNO3 affects the CFs’ microwave properties. The CFs were characterized by SEM and TEM, and oxygen-containing surface groups were quantified by thermal analysis methods. Treatment with H2O2 and HNO3 solutions increased the oxygen content to about 6 at% and up to 10 at%, respectively, which decreased the reflection loss and increased the transmission loss at 25.86–37.5 GHz. The microwave properties showed pronounced correlations with the concentration of HNO3 and not with H2O2, indicating that the HNO3 oxidant is more promising for microwave loss tuning.