Improved dispersion of carbon nanotubes in poly(vinylidene fluoride) composites by hybrids with core-shell structure

Core-shell structure hybrids of carbon nanotubes (CNTs)/BaTiO₃ (H-CNT-BT) and commercial multi-wall CNTs are respectively incorporated into poly(vinylidene fluoride) (PVDF) for preparing the composites near the percolation thresholds. A comprehensive investigation for CNT’s dispersion and composite’s conductivity is conducted between H-CNT-BT/PVDF and CNT/PVDF at different depths vertical to the injection’s direction. Gradual increases of the conductivity in two composites are observed from the out-layer to the core part which infers an inhomogeneous CNT’s dispersion in the interior of composites due to their migration under flow during the injection. However, the use of H-CNT-BT fillers with core-shell structure enables to reduce this inhomogeneous dispersion in the composite. Furthermore, the conductive network of CNTs in H-CNT-BT/PVDF is less sensitive to the thermal treatment than the one in CNT/PVDF composite, which infers the core-shell structure of hybrids can ameliorate the sensitivity of the conductive network.