Enhanced corrosion resistance of flaky carbonyl iron through dual silane surface modification for the application of electromagnetic wave absorption coatings

Surface modifications are efficient techniques to enhance the corrosion resistance of flaky carbonyl iron (FCI) for electromagnetic wave absorbing coatings. However, with the emergence of diverse harsh service environments (tropical marine climate, etc.), it becomes more challenging for traditional single-layer modification of FCI to meet the durability requirements. Here, a facile synthesis method for enhancing the corrosion resistance of FCI was developed by dual silane surface modifications. The corrosion behaviors of FCI with and without dual silane surface modifications were investigated by immersing in a corrosive environment (chemical corrosion) and electrochemical testing. Following immersion tests, the dual layer modified FCI exhibits the highest remaining solid mass, the highest self-corrosion potential, the largest polarization resistance, and the lowest corrosion current density. In addition, the dual layer modified FCI maintains a decent electromagnetic wave absorption ability which reaches the minimum value of the reflection loss ( \({RL}_{min}\) ${\mathit{RL}}_{\mathit{min}}$ ) of − 21 dB with a thickness of 3 mm. Therefore, designing a dual coated structure provides a promising scalable strategy to enhance the applicability of electromagnetic wave absorption coating during service in diverse field conditions.