Facile fabrication of PPy/MWCNTs composites with tunable dielectric properties and their superior electromagnetic wave absorbing performance

Enhanced interfacial polarization is one of the most effective methods for efficient electromagnetic wave absorbing (EMA) performance. In this study, we propose a cladding morphology modulation strategy for preparing high-performance PPy/MWCNTs(PC) by controlling the polymerization cladding morphology of PPy through acid doping using an in-situ polymerization method. By constructing a 3D network structure with a rough surface, many interfaces and pore spaces are generated to increase the multiple reflections and scattering of electromagnetic wave energy, improve the interfacial polarization of the material, and enhance the polarization relaxation process. Meanwhile, the 3D conductive network generated by the cladding provides a channel for electron transfer between MWCNTs and PPy nanoparticles and PC nanorods, which improves the conductivity loss of the material and allows more electromagnetic wave to be dissipated in the form of thermal energy. With the doping acid of p-toluene sulfonic (TsOH), the EMA absorption performance of PC composites can reach a maximum reflection loss( \({RL}_{min}\) ${\mathit{RL}}_{\mathit{min}}$ ) of -60.21 dB at the frequency of 8.24 GHz, and the best effective bandwidth (EAB_max) of 5.04 GHz for single thickness and 14.08 GHz for full-thickness (EAB_sun), providing excellent EMA performance.