Hybrid percolation network in composite for selectively enhancing electrical and thermal conductivities

Filler percolation network can improve the transport properties in composite, which is usually coupling to enhance electrical and thermal conductivities even it is undesired. In the present study, we demonstrate that adding a spot of nanoparticles as secondary filler in composite can realize selectively enhancing the transport properties. For high thermal and low electrical conductivities, the electrical conductivity in hybrid composite (conductive nanoplate as primary filler) with dielectric nanosphere (NS) as second filler decreases by similar to 98% (NS proportion in all filler, phi(NS)/phi, is 0.2) than pure composite due to the abruption of conductive network by NS, while the change of thermal conductivity is negligible. For high electrical and low thermal conductivities, a similar to 60% enhancement of electrical conductivity in hybrid composite with metallic NS as second filler is found at phi(NS)/phi similar to 0.14, and meanwhile, the thermal conductivity distinctly decreases. Our study shows a strategy to tailor the transport properties in composite, which may facilitate the applications of interfacial heat dissipation and thermoelectric conversion. (C) 2019 Elsevier Ltd. All rights reserved.