Enhanced electromagnetic wave absorption of polar absorber hybrids self-assembled by MWCNTs and sulfonated polystyrene microsphere

Polar absorber hybrids containing sulfonic groups with a three-dimensional architecture were self-assembled by the incorporation of sulfonated polystyrene microspheres (PS-SO₃H) and multi-walled carbon nanotubes (MWCNTs). The influence of polar sulfonic groups of PS microspheres on the microwave absorption of MWCNTs was presented. The structure and morphology of absorber hybrids were characterized by Raman, FTIR, XPS, SEM and TEM. The results of SEM and TEM proved that the continuous conductive network was constituted and the dispersity of MWCNTs was promoted, which is attributed to the framework support of sulfonated PS microspheres among MWCNTs and self-assembly effect induced by π–π stacking and p–π electron conjugation. The polar absorbers hybrids of PS-SO₃H@MWCNTs exhibited preeminent absorbing performance. The maximum reflection loss was − 39.22 dB at 12.33 GHz, and the bandwidth correspond to the reflection loss below − 10 dB was 1.82 GHz. In contrast, the maximum reflection loss of nonpolar PS@MWCNTs hybrid was − 25.22 dB at 9.04 GHz and the bandwidth below − 10 dB was 1.60 GHz. The results indicate that the polar groups have crucial impact on the enhanced absorbing performance, which can help to prepare a promising microwave absorbing materials in 2–18 GHz frequency for absorbing applications.