Comparative study on solid and hollow glass microspheres for enhanced electromagnetic interference shielding in polydimethylsiloxane/multi-walled carbon nanotube composites

Herein, solid and hollow glass microspheres (SGM and HGM) were added into polydimethylsiloxane/multi-walled carbon nanotube (PDMS/MWCNT) composites to induce multiple interfaces. The electromagnetic interference (EMI) shielding of the PDMS/MWCNT composites was expectedly enhanced by the multiple reflection and/or scattering at the interfaces between GM and PDMS/MWCNT phase. The EMI shielding effectiveness (SE) of the PDMS/MWCNT composites with 3.0 vol% MWCNT fillers increased from similar to 40 to similar to 52 dB and 46 dB by the addition of 30 vol% SGM and HGM, respectively. The high specific SE value was found in the composites with HGM due to the low density of the samples with HGM. The effect of the diameter and the content of SGM, the content of MWCNT, and the sample thickness on EMI SE of the PDMS/MWCNT/SGM composites were investigated in this work. The high-performance EMI SE were achieved in the composites by balancing the thickness of conductive layers and the amount of multiple reflection and/or scattering interfaces.