The composite of TiO2 particles and Na2Ti6O13 whiskers for microwave absorption via a NaCl crystal-assisted sol-gel method

The development of heterogeneous interfaces has emerged as an efficient strategy for enhancing the microwave absorption (MA) properties of absorbers. This study presents the effective synthesis of the composite of TiO ₂ particles and Na ₂Ti ₆O ₁₃ whiskers (TN whiskers) using a NaCl crystal-assisted sol-gel method. By adjusting the polarization sites induced by whiskers intertwine degree, the TN/paraffin composites achieve a minimum reflection loss (RL _min) of − 43.8 dB at 14.8 GHz and 2.9 mm thickness, corresponding to an effective absorption bandwidth (EAB) of 3.84 GHz. Additionally, the EAB reaches up to 4.32 GHz at 3.2 mm. The MA mechanisms are attributed to the impedance matching (IM), which is of nearly 1 in the frequency range of 10–16 GHz, and from polarization loss induced by interfacial polarization (TiO ₂/Na ₂Ti ₆O ₁₃) and defect dipole polarization ( T i T i ′ , V O ∙ ∙ , N a T i ′ ′ ′ , T i 3 + → V O ∙ ∙ ← T i 3 + , T i 4 + + e → T i 3 + ). Hence, the investigation of TN whiskers as an original absorber presents a novel and promising research direction.