Choi, Jiho Lee, Yejung Chae, Yangki Kim, Sung-Soo Kim, Tae-Hwan Lee, Sungho 2024-01-19T11:02:44Z 2024-01-19T11:02:44Z 2022-09-02 2022-10 0008-6223 https://pubs.kist.re.kr/handle/201004/114516 Despite extensive studies on structural changes during the carbonization process of pitch-derived fibers, an ac-curate description of the transformation from liquid crystalline domains into carbon crystallites is still limited to a few depictions based on common analytical tools for carbon fibers. We employed small-angle X-ray scattering (SAXS) with model fits for the unification of such disparate measures. The carbonization process below 1200 ? is divided into three sequential regimes: Regime I -disruption of stacked polyaromatic mesogens with fluctuations in elasticity from 300 to 600 ?; Regime II -full-scale transformation with enhancement in orientation from 600 to 800 ?; and Regime III -development of semi-crystalline carbon structures with elongation of microvoids from 800 to 1200 ?. By examining the viscoelastic properties of pitch-derived fibers during heat treatment below 600 ? (Regime I), we found that the maximum softness of the pitch-derived fibers is achieved at 500 ?. This is due to the decrease in crosslink density between stacking structures, indicating that the crosslink density below 600 & DEG;C is a significant contributor to the formation of carbon crystallites. English Pergamon Press Ltd. Unveiling the transformation of liquid crystalline domains into carbon crystallites during carbonization of mesophase pitch-derived fibers Article 10.1016/j.carbon.2022.08.033 1 Carbon, v.199, pp.288 - 299 Carbon 199 288 299 Y scie scopus 000843947900004 Chemistry, Physical Materials Science, Multidisciplinary Chemistry Materials Science Article GRAPHITIZATION POLYACRYLONITRILE EVOLUTION GRAPHITE RAMAN MICROSTRUCTURES CONDUCTIVITY FABRICATION PRECURSORS MICROSCOPY Mesophase pitch Carbon fiber Microstructure SAXS