The controlled formation of hybrid structures of multi-walled carbon nanotubes on SiC plate-like particles and their synergetic effect as a filler in poly(vinylidene fluoride) based composites Original Research Article

Vertically aligned carbon nanotubes (CNTs) grown on plate-like SiC microparticles as nano/micro hybrid structures were produced by floating catalytic chemical vapor deposition. Acetylene and ferrocene were used as carbon source and catalyst precursor, respectively. The effect of experimental conditions on the structure of the CNT-SiC multi-scale hybrids produced was investigated. The results indicated that the organization mode of CNTs on SiC particles could be effectively tuned by changing the hydrogen content in the carrier gases. The effect of the substrate on the hybrid structures was also studied and their formation mechanism was discussed. According to X-ray diffraction and Raman spectra, the asymmetric surface properties of 6H-SiC tended to produce “single-direction” growth of CNTs on SiC particles, while the competition between the nature of the substrate and the experimental conditions can result in a “multi-direction” hybrid structure. The resultant well-organized CNT-SiC hybrid structures can be further used as conductive filler to prepare percolative poly(vinylidene fluoride) composites. The composites containing the “single-direction” hybrid structures exhibited a much lower percolation threshold than those with “multi-direction” hybrid structures. The percolation behavior of the composites can be tuned by controlling the structure of CNT-SiC hybrids.