Influences of Tunneling Distance and Interphase Size on the Conductivity of Graphene-Filled Nanomaterials

The effects of tunneling parts and interphase on the conductivity of graphene-filled polymer materials were neglected in the modeling papers. This work expresses a developed methodology for conductivity of graphene-filled polymer systems supposing the main tunneling mechanism. The tunneling distance depends on the percolation inception and concentration of graphene nanosheets. Additionally, the percolation inception and the effective volume fraction of nanofiller are associated with filler dimensions and interphase thickness. So, the established model can suggest the conductivity by the content and dimensions of graphene, interphase thickness and percolation inception. The parameters’ effects on the tunneling distance and conductivity are discussed. Moreover, some samples are provided and their tested values for percolation inception and conductivity are utilized to calculate and analyze the interphase thickness, volume fraction of interphase region, tunneling distance and electrical conductivity using the developed equations. The examinations of parameters and experimental results confirm the correctness of the presented equations. Big and thin nanosheets along with a dense interphase grow the nanoparticle’s effectiveness and diminish the percolation inception developing the conductivity of samples.