Stabilization and Carbonization of PAN Nanofiber Mats Electrospun on Metal Substrates

Polyacrylonitrile (PAN) nanofiber mats are typical precursors for carbon nanofibers. They can be fixed or even elongated during stabilization and subsequent carbonization to gain straight, mechanically robust carbon nanofibers. These processes necessitate additional equipment or are-if the nanofiber mats are just fixed at the edges-prone to resulting in the specimens breaking, due to an uneven force distribution. Hence, we showed in a previous study that electrospinning PAN on aluminum foils and stabilizing them fixed on these substrates, is a suitable solution to keep the desired morphology after stabilization and incipient carbonization. Here, we report on the influence of different metallic and semiconductor substrates on the physical and chemical properties of the nanofiber mats after stabilization and carbonization at temperatures up to 1200 degrees C. For stabilization on a metal substrate, an optimum stabilization temperature of slightly above 240 degrees C was found, approached with a heating rate of 0.25 K/min. Independent from the substrate material, SEM images revealed less defect fibers in the nanofiber mats stabilized and incipiently carbonized on a metal foil. Finally, high-temperature carbonization on different substrates is shown to allow for producing metal/carbon nano-composites.

Automated summary

Electrospinning PAN onto aluminum foils and stabilizing them on the substrates is an effective solution for maintaining the desired morphology during stabilization and incipient carbonization. Stabilization on a metal substrate at slightly above 240 degrees C with a heating rate of 0.25 K/min leads to fewer defect fibers in the resulting nanofiber mats. High-temperature carbonization on different substrates enables the production of metal/carbon nano-composites.