Tunable Dielectric Properties of Carbon Nanotube@Polypyrrole Core-Shell Hybrids by the Shell Thickness for Electromagnetic Wave Absorption

Carbon nanot,ube@polypyrrole(CNT@PPy)hybrids have been successfully fabricated via a simple in situ chemical oxidation polymerization.The thickness of the PPy shell can be finely controlled in the range of 3.06.4 nm.The dielectric loss of core-shell hybrids can be tuned by the shell thickness,resulting in a well-matched characteristic impedance that can enhance electromagnetic wave(EMW)absorption performance.Minimum reflection loss of the hybrid with moderate PPy shell thickness can reach-51.4 dB at 11.8 GHz with a matching thickness of merely 2mm.Furthermore,the minimum reflection loss values of the hybrid are below-30 dB even at thickness in the range of 1.4-1.9mm,endowing the possibility of practical application of the hybrids in electromagnetic wave absorption field.