Properties and formation mechanisms of branched carbon nanotubes from polyvinylidene fluoride fibers

Branched carbon nanotubes (b-CNTs) were synthesized via a very simple process where polyvinylidenefluoride (PVDF) fibers containing H2PtCl6 were partly dehydrofluorinated and then subjected to carbonization at high temperature under a nitrogen atmosphere. During the process, the solid polymeric fibers were converted to carbon nanotubes with branches growing on the surface of the tubes. The carbon branches started to grow at around 500 °C, and the growth terminated at around 700 °C. The gaseous species generated during the carbonization process were identified using in situ mass spectroscopy. Based on the analytical data, a mechanism for the formation of the b-CNTs is proposed.