Modified nano-magnetite coated carbon fibers magnetic and microwave properties

In this work, a lightweight double layered composite with excellent, mechanical and electromagnetic (EM) absorption properties was fabricated. The structure, morphology, magnetic and microwave absorption properties of prepared samples and bonding strength between the double-layer coatings were investigated. In order to prepare the composite samples, a multi-step cathodic method employed to deposite magnetite on the surface of activated carbon fibers (CFs) through the reduction of Fe (III)–Triethanolamine complex in an aqueous alkaline solution at 60–80 °C. Our results indicated that, a more homogenous and denser magnetite coating and consequently, improved EM absorption properties could be achieved by multi-step electro-deposition method on CFs comparing to single step method. Furthermore, a porous flake-like layer of magnetite was formed uniformly at 60 °C, while a dense and discontinuous layer with globular nano-particles deposited on the surface of CFs at 80 °C.