Superior wave-absorbing performances of silicone rubber composites via introducing covalently bonded SnO₂@MWCNT absorbent with encapsulation structure

SnO₂@MWCNT wave absorbent was firstly fabricated via a hydrothermal process followed by heat treatment. Then SnO₂@MWCNT/silicone rubber wave-absorbing composites were obtained by solution casting method. XRD, Raman, TGA, XPS, and TEM analyses indicated the successful preparation of covalently bonded SnO₂@MWCNT absorbent with encapsulation structure. When the mass fraction of SnO₂@MWCNT was 7.5 wt% and the sample thickness was 2.6 mm, the SnO₂@MWCNT/silicone rubber wave-absorbing composite displayed the minimum reflection loss (RL_min) of −56.9 dB and effective absorption bandwidth (EAB) of 3.1 GHz. The outstanding wave-absorbing performances of SnO₂@MWCNT/silicone rubber wave-absorbing composites could be ascribed to the excellent impedance matching and dielectric loss capability. Furthermore, the corresponding 7.5 wt% SnO₂@MWCNT/silicone rubber wave-absorbing composite exhibited heat resistance index (T_HRI) of 196.3 °C, higher than that of neat silicone rubber (187.4 °C).