Electromagnetic interference shielding effectiveness and skin depth of poly(vinylidene fluoride)/particulate nano-carbon filler composites: prediction of electrical conductivity and percolation threshold

摘要

The addition of various particulate nano-carbon (PNC) fillers to heat-resistant poly(vinylidene fluoride) (PVDF) was carried out to prepare conductive composites for use in electromagnetic interference (EMI) shielding application. Three different PNC fillers, namely N472 (Vulcan XC-72), N550 (Fast Extruding Furnace) and N774 (Semi-Reinforcing Furnace), were used in various concentrations to prepare composite systems PVDF/N472, PVDF/N550 and PVDF/N774 by solution casting followed by a moulding technique. These PNC fillers have a particle size at the nanometre level, but they have an aggregating tendency; both these characteristics influence the properties of composites to which such fillers are added. The percolation threshold of the PVDF/PNC composites was theoretically determined using the sigmoidal Boltzmann model and classical theory and compared. Theoretical models were also used to predict composition-dependent electrical conductivity. The electrical conductivity is correlated to that of EMI shielding effectiveness at ambient temperature. (c) 2019 Society of Chemical Industry