A novel methodology to describe the impact of conduction transporting via a deficient interphase on the conductivity of carbon nanofiber composites

A deficient interphase is considered to express the percolation threshold ( ϕ p ) and conductivity for carbon nanofiber (CNF)-filled composite (PCNF) using a modeling approach. In this context, Y represents the extent of conduction transfer via a deficient interphase in the PCNF and is expressed using the interphase depth ( t ) and CNF radius ( R ). The actual features of the CNFs (aspect ratio, volume portion and ϕ p ) and amount of the interphase/CNF net are stated by Y . Besides, a novel model is proposed for the PCNF conductivity by the degree of conduction transport, tunneling distance, and effective parameters. Predictions of the newly developed equations for Y , ϕ p , and PCNF conductivity are evaluated using parametric analyses. Thinner CNFs and denser interphases enhance the Y but decrease the percolation threshold. The PCNF conductivity increases to 0.154 S/m at Y = 15 and ϕ p = 0.002, whereas ϕ p > 0.016 results in an insulating PCNF. Moreover, R = 40 nm and t = 35 nm grow the nanocomposite conduction to 0.25 S/m, though an insulative sample is found at R > 75 nm or t < 16 nm. Consequently, a higher extent of Y , lower percolation threshold, narrower CNFs, and deeper interphase contribute to increased nanocomposite conductivity. However, excessively high percolation thresholds and CNF radii or an insufficiently thick interphase fail to enhance PCNF conductivity.