Monte Carlo analytical-geometrical simulation of piezoresistivity and electrical conductivity of polymeric nanocomposites filled with hybrid carbon nanotubes/graphene nanoplatelets

Abstract

Piezoresistivity and electrical conductivity of carbon nanotube (CNT)/graphene nanoplatelet (GNP)-filled polymer nanocomposites are investigated using a 3D Monte Carlo analytical-geometrical model. GNPs and CNTs are considered as randomly distributed solid thin rectangular cube and cylinder, respectively. After establishment of a random CNT/GNP network, electrical conductivity and relative resistance change with strain is calculated. Model considers effect of CNT and GNP deformation on filler separation distance as the dominant factor for percolation tunneling. Comparing model results with experimental data of hybrid nanocomposites showed a good agreement for electrical conductivity and piezoresitivity. Analytical model is developed on the basis of geometrical tunneling percolation theory to consider the effect of several parameters like height of barrier potential, GNP side length, CNT orientation and dimensions on electric behavior of nanocomposites. Results revealed that CNT dispersion state and GNP dimensions have significant effects on the percolation threshold and resistivity change ratio of nanocomposites with strain.