Preparation and microwave absorption properties of flexible composites containing Ag decorated polystyrene powders

Polystyrene(PS)microspheres have the advantages of good stability,corrosion resistance and low density,which have a broad application prospect.In this paper,PS composite microspheres with 20%silver plating content were prepared by chemical plating method and incorporated into polydimethylsiloxane(PDMS)flexible matrix to prepare Ag@PS/PDMS flexible wave-absorbing materials.The electromagnetic parameters were adjusted to optimize the dielectric and wave-absorbing properties by varying the additional amount of Ag@PS composite microspheres in Ag@PS/PDMS composites.The X-ray diffraction(XRD)results proved the successful preparation of Ag@PS composite microspheres.The SEM and EDS images indicated that the Ag particles were attached to the external surface of PS.The presence of Ag particles in the Ag@PS composite microspheres enhances their electrical conductivity and enables the formation of a conductive network.This,in turn,improves the composites’dielectric constant.The optimal wave-absorbing capability of the composites was achieved when the Ag@PS composite microspheres were added at a weight percentage of 50%.When the sample attains a thickness of 1.8 mm,a reflection loss of at least-39.8 dB is attained at 10.4 GHz,along with a bandwidth of 1.6 GHz(9.1–10.7 GHz)for the effective absorption bandwidth(EAB).The pressure-sensitive properties of the pliable composites were investigated as well.The optimal pressure-sensitive performance of Ag@PS/PDMS composites was achieved with a 60 wt.% addition of Ag@PS composite microspheres.The resistance undergoes significant changes when subjected to pressure with a sensitivity of 9.7.The results indicate that the flexible composites’wave-absorption and pressuresensitivity properties can be modulated by adjusting the amount of Ag@PS composite microspheres added.