Highly conductive polystyrene/carbon nanotube/PEDOT:PSS nanocomposite with segregated structure for electromagnetic interference shielding

Highly conductive polymer nanocomposites (CPNs) are promising alternatives to metals for electromagnetic interference (EMI) shielding applications. However, constructing a well-established conductive network within a polymer matrix using conventional processes is still challenging. This research aimed to improve the EMI shielding performance of CPNs by developing highly conductive segregated structures through a facile innova-tive dispersion mixing process. The nanocomposites were fabricated by dispersing polystyrene beads (PS), CNT, and PEDOT:PSS in deionized water, followed by vacuum filtration, solvent treatment, and hot press molding. The employed technique effectively constructed a highly conductive network in the PS/CNT nanocomposite, resulting in the lowest ever reported percolation threshold of 0.009 vol% among CNT-based segregated struc-tures. Moreover, adding PEDOT:PSS to the nanocomposite as an additional constituent significantly promoted the conductive network by improving the dispersion of CNTs and the interparticle contact. The PS/CNT/PEDOT: PSS (100:2:4 w/w/w) exhibited a high electrical conductivity of 2.352 S/cm with notable specific EMI shielding effectiveness (SE) of 55.7 dB/mm (with dominant absorption mechanism), which is among the best performance reported for CNT-based conductive segregated structures, to the best of our knowledge. In brief, this work proposed a novel approach of using a facile, cost-effective, and eco-friendly method to fabricate highly CPNs for EMI shielding applications.

Automated summary

This research aimed to improve the EMI shielding performance of highly conductive polymer nanocomposites (CPNs) by developing segregated structures through a dispersion mixing process. The nanocomposites were fabricated by dispersing polystyrene beads (PS), CNT, and PEDOT:PSS in deionized water, followed by filtration, treatment, and molding. The technique effectively constructed a highly conductive network in the PS/CNT nanocomposite, resulting in the lowest percolation threshold reported for CNT-based structures. Additionally, adding PEDOT:PSS significantly enhanced the conductive network. The PS/CNT/PEDOT:PSS nanocomposite exhibited high electrical conductivity and specific EMI shielding effectiveness.