Facile fabrication of highly conductive polystyrene/nanocarbon composites with robust interconnected network via electrostatic attraction strategy

An electrostatic attraction strategy was employed for the preparation of highly conductive composites using commercialized graphene or multi-walled carbon nanotubes (MWCNTs) as conductive fillers and polystyrene (PS) microspheres as the resin matrix. The PS microspheres were first sulfonated to endow them with a highly negatively charged surface while the nanocarbons were positively charged in water using an amino-functionalized perylene bisimide as a stabilizer. Direct mixing of the sulfonated PS microsphere and the aqueous nanocarbon dispersion produced agglomerates with PS-nanocarbon core-shell structure due to electrostatic attraction interaction. An interconnected conductive network was formed after hot-pressing the agglomerates. Because of the strong electrostatic attraction and the high T-g temperature of the sulfonated layer, the interconnected conductive network was well-preserved even at a low filler content or a high hot-pressing temperature, resulting in an ultralow percolation threshold of the composites (<0.047 vol%) and conductivity up to 104 S m(-1) at a graphene content of 4.51 vol%, and to 391 S m(-1) at a MWCNTs content of 3.20 vol%. The above approach is time-saving and applicable to the manufacture of other conductive polymer-based composites.