Microwave absorption properties and infrared emissivities of ordered mesoporous C-TiO2 nanocomposites with crystalline framework

Ordered mesoporous C-TiO₂ nanocomposites with crystalline framework were prepared by the evaporation-induced triconstituent co-assembly method. The products were characterized by XRD, TEM, N₂ adsorption-desorption and TG. Their microwave absorption properties were investigated by mixing the product and epoxy resin. It is found that the peak with minimum reflection loss value moves to lower frequencies and the ordered mesoporous C-TiO₂ nanocomposite possesses an excellent microwave absorbing property with the maximum reflection loss of −25.4 dB and the bandwidth lower than −10 dB is 6.6 GHz. The attenuation of microwave can be attributed to dielectric loss and their absorption mechanism is discussed in detail. The mesoporous C-TiO₂ nanocomposites also exhibit a lower infrared emissivity in the wavelength from 8 to 14 μm than that of TiO₂-free powder.