Mechanistic Insights\ninto the Evolution of Graphitic\nCarbon from Sulfur Containing Polar Aromatic Feedstock

In the realm of carbon fiber research, a variety of structural\nconfigurations is noted, comprising crystalline, noncrystalline, and\nsemicrystalline forms. Recent investigations into this domain have\nrevealed an array of intriguing phases of carbon, among which amorphous\ngraphite is the most notable for its unique mechanical, thermal, and\nelectrical properties that arise from its inherent topological disorders.\nIn this study, we utilized the ReaxFF molecular dynamics (MD) simulations\nto investigate the carbonization and graphitization processes involved\nin the production of amorphous graphite from benzothiophene, a sulfur-containing\npolar aromatic precursor. We developed C/H/S ReaxFF force field parameters\nto describe the high-temperature chemistry of benzothiophene. Our\ninvestigation reveals the reaction mechanisms, providing critical\ninsights into the underlying chemical processes toward the formation\nof amorphous graphite and the structural characteristics of the end\nproducts. The formation of volatile gaseous molecules and their continuous\nelimination led to the development of noncontinuous layered graphite\nstructures analogous to amorphous graphite consisting of pentagons,\nhexagons, and heptagons. These findings offer unprecedented insights\ninto the carbonization and graphitization processes of sulfur-containing\nheavy-end aromatic feedstock. This knowledge lays the groundwork for\nadvancing synthesis methods and developing amorphous graphite materials\nwith specific properties.