Synthesis of Ag@SrFe₁₂O₁₉@carbon fiber microwave absorption composite and its application in PVC resin

An excellent Ag@SrFe₁₂O₁₉@CF microwave absorbing material was synthesized by a facile two-step reaction of hydrothermal reaction and electroless silver plating. The surface morphology and chemical components of the compounds have been analyzed via SEM and XRD. The results suggest that the surface of CF was covered by SrFe₁₂O₁₉ grains completely and Ag layer wraps the obtained SrFe₁₂O₁₉@CF successfully. The conductivity and the saturation magnetization (Ms) of the obtained Ag@SrFe₁₂O₁₉@CF are 4.5 S/cm and 31.2 emu/g, respectively. The vector network analysis indicated that the Ag@SrFe₁₂O₁₉@CF exhibits better microwave absorbing ability than that of CF and SrFe₁₂O₁₉@CF. The maximum reflection loss value of the composite with a thickness of 2.0 mm is −36 dB at 9.0 GHz and the bandwidth of reflection loss less than −10 dB is 2.0 GHz (from 8.2 to 10.2 GHz). When the Ag@SrFe₁₂O₁₉@CF was applied to modify the PVC resin, the 15 wt% PVC@Ag@SrFe₁₂O₁₉@CF’s reflection loss value can reach −21 dB. The PVC@Ag@SrFe₁₂O₁₉@CF composite’s microwave absorbing properties are excellent.