Effective length of carbon nanofiber due to an inadequate interphase to optimize the percolation onset and tunneling conductivity of composites

Polymer nanocomposites customarily comprise an inadequate interphase failing their properties, but this topic was rarely addressed in the former reports. Herein, the efficient carbon nanofiber (CNF) length ( l eff ) in the CNF-filled composite (PCNF) is expressed by interphase conductivity, interphase depth, CNF features and Y (level of conduction transferring via an inadequate interphase). Then, l eff is used to define the percolation starting and netting ratio. Similarly, a model is progressed for PCNF conductivity (PEC) by the mentioned parameters and tunneling size. The stimuli of momentous factors on the effective length of CNFs, percolation starting and PEC are patterned and explicated. In addition, many experimented data of percolation starting and PEC are provided to assess the developed equations. Higher Y , slender CNFs, thicker interphase and higher interphase conductivity produce the bigger l eff and lower percolation starting improving the PEC. Y = 20 and CNF radius ( R ) of 40 nm promote the PEC to 0.16 S/m, while Y = 5 and R = 120 nm produce an insulative PCNF. Likewise, tunneling size ( λ) of 1 nm together with contact width ( d ) of 60 nm encourage the PEC of 0.45 S/m, whereas a nonconductive composite is shown at λ > 9 nm or d < 20 nm. Hence, the shortest tunnels and the highest contact width noticeably grow the PEC.