Multifunctional sensing properties of polymer nanocomposites based on hybrid carbon nanostructures

The electrical, mechanical, piezoresistive and thermoresistive properties of polysulfone nanocomposites with a total filler concentration of 1 wt.%, using a hybrid combination of multilayer graphene sheets (GSs) and multiwall carbon nanotubes (CNTs) in various relative proportions are investigated. Nanocomposites with only CNTs presented, by far, the highest electrical conductivity, downplaying the role of GSs to improve the electrical conductivity of CNT nanocomposites. On the other hand, adding amounts of CNTs as small as 25 % of the total weight filler concentration, greatly benefited the electrical conductivity of GS nanocomposites. Mechanical properties were also not significantly benefited from the addition of GSs, but important collaborative effects between both types of fillers were found when the nanocomposites were subjected to tensile strain and variations in temperature, improving the piezo- and thermo-resistive sensitivities of the nanocomposites.