Accelerated Graphitization of PAN-Based Carbon Fibers: K⁺-Effected Graphitization via Laser Irradiation

Abstract

Graphitization progress of polyacrylonitrile (PAN)based carbon fibers is closely dependent on the treatment temperature; exactly, controlling the microstructural morphology of carbon layers in the fibrous solid state can accelerate the formation of a highly graphitic structure. The present work exhibited the accelerated graphitization of PAN-based carbon fibers by the effect of K + on microstructure evolution under laser irradiation. Chemical and microstructure characterization reveals that a much higher degree of graphitization is achieved via the K + effect after the laser irradiation than by pure laser treatment at the same low temperature of about 2000 °C. Ordered and large-sized graphite-like microcrystals can be formed as well. The reactive molecular simulation further provided insights into the acceleration mechanism of the K + effect during the graphitization progress. Thus, based on these results, K + -effected graphitization via laser irradiation can be a promising alternative for the efficient and eco-friendly mass production of graphite fibers.

Direct Laser Writing: From Materials Synthesis and Conversion to Electronic Device Processing

“…Under inert atmospheres, film and substrate contamination can be avoided, while the absence of reactive volatiles suppresses the occurrence of possible oxidation or combustion promoted by the presence of oxygen. [125,126] These inert atmospheres are usually developed by permeating the working chamber with inert gases [125] or injecting these gases through a nozzle directed at the irradiated area, [127] being argon [29,126,[128][129][130] or argon/H 2 mixture (95:5) [125,127] the most common choices. Other gases have been employed for atmosphere control in irradiation procedures, to accelerate certain reactions, for example, reduction, or to suppress plasma and exacerbated heat accumulation, [94] where nitrogen flow stands out.…”