Graphene Nano-sheets/Multi-walled Carbon Nanotubes/Polyvinyl Alcohol Composite Films: Effects of Hybrid Fillers on Electromagnetic Interference Shielding Effectiveness
This study employs the solution mixing method to produce composite films by using polyvinyl alcohol (PVA), graphene nano-sheets (GNs), and multi-walled carbon nanotubes (MWCNTs). Tensile test, differential scanning calorimetry (DSC), four-point probe/coaxial transmission line method are performed in order to evaluate the tensile properties, melting and crystallization behaviors, electric conductivity, and electromagnetic interference shielding effectiveness (EMI SE) of the composite films. The test results indicate that with the increasing amount of MWCNTs, GNs/MWCNTs hybrid fillers cause a synergy effect that contributes to the tensile strength of the composite films. An optimal GNs/ MWCNTs ratio is 0.5 wt%:1wt% that provides the films with a tensile property of 19.6 MPa, an improvement on glass transition temperature (Tg), melting temperature (Tm) and crystallization temperature (Tc) of PVA, an electric conductivity of 2.6×10-5 S/cm, and EMI SE of -15 dB at frequency 1 GHz-2 GHz that is equal to a 99.9 % shielding level required by livelihood necessities.