Preparation of CIP@TiO₂ composite with broadband electromagnetic wave absorption properties

It is meaningful to improve the impedance matching of the material while maintaining its excellent wave absorption properties. In this paper, according to the hydrolysis characteristics of isopropyl titanate (TTIP), a simple preparation process of carbonyl iron powder (CIP) coated with TiO₂ was designed. Due to the coated TiO₂, the impedance matching of the CIP@TiO₂ composite was well adjusted by decreasing the dielectric constant. Moreover, the interfacial polarization of CIP@TiO₂ has also been enhanced. Ultimately, the electromagnetic wave (EMW) absorption property of CIP@TiO₂ composite was significantly improved, the minimum reflection loss (RL_min) reach -46.07 dB, and the effective absorption bandwidth (EAB) can reach 8 GHz when the thickness is only 1.5 mm. Moreover, compared the CIP, the oxidation resistance of CIP@TiO₂ was significantly improved. The results shown that the oxidation starting temperature of CIP@TiO₂ is 400^oC, whereas uncoated CIP has an oxidation starting temperature of about 250^oC. Moreover, the largest oxidation rate temperature of CIP@TiO₂ was increased to about 550^oC. This work opens up a novel strategy for producing high-performance EMW absorbers with the help of structure design.