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Carbon‐based materials are widely deployed in carbon capture but are only limited to physisorption procedures. Further extending functionalized carbon materials to CO2 chemisorption under low CO2 concentration is highly desirable yet challenging. Herein, a carbon fiber composed of solely ultra‐micropores (∼0.45 nm) was deployed as the precursor to avoid the pore blocking effect, which was modified by superbase‐derived ionic liquids (ILs) containing strong interaction sites with CO2. By forming a thin coating layer on the surface, the as‐afforded surface‐functionalized fiber materials demonstrated enhanced CO2 uptake capacity and improved CO2 sorption kinetics, as evaluated by both the volumetric method and thermogravimetric analysis, as well as the calculated energy distribution curves. The achievements made in this work provide guidance on the functionalization of carbon‐based materials towards enhanced CO2 chemisorption by forming a thin layer of selected IL coating. [ABSTRACT FROM AUTHOR]

Carbon fiber (CF) is a versatile material renowned for its excellent mechanical, thermal, and electrical properties. Polyacrylonitrile (PAN)-based CFs dominate the market in part due to their high tensile strength, rendering them suitable for structural applications in a wide variety of applications ranging from sporting goods to aerospace. Over five decades of commercial development of PAN-based CF has resulted in a range of varieties with different tensile moduli and tensile strengths. The microstructures, nanostructures, and crystal structures of PAN-based CF all play pivotal roles in the macroscale properties of this material. In particular, the crystal structure and crystallite orientation in CF is closely related to the mechanical properties. The crystal structure of PAN-based CF generally consists of turbostratic carbon, a disordered form of graphite, the characteristics of which can be effectively characterized in a bulk format through wide-angle x-ray diffraction (WAXD). In this work, we employed a three-part approach to the analysis of WAXD patterns collected from four intermediate modulus PAN-based CFs. The approach incorporates a Scherrer analysis, a Debye analysis, and an orientational analysis to provide precise estimates of crystallite sizes, crystallite distributions, and crystallite orientations with the fiber axis. The results presented here suggest that intermediate modulus PAN-based CF mostly consists of small turbostratic crystallites (<4 nm), with larger crystallites having increased orientation with the fiber axis. The results here imply the presence of curvature and/or wrinkling of the turbostratic layers within the CF structure. [Display omitted] [ABSTRACT FROM AUTHOR]

Mild direct coal liquefaction (autogenous pressure, no catalyst, no H 2 gas) of Springfield coal in fluid catalytic cracking decant oil is shown to effectively produce coal extract precursors to spinnable mesophase pitch. This work demonstrates that the coal extract can be thermally treated to obtain mesophase pitch in a facile one-step process, bypassing the production of an intermediate isotropic pitch. Furthermore, the presence of 25 wt.% coal in the initial slurry can increase the yield to mesophase pitch nearly twofold and yield to carbon fiber by approximately 70%. The coal extract-derived mesophase pitch was melt-spun and heat treated to produce carbon fiber with graphitic texture, high modulus (>400 GPa) and tensile strength up to 943 MPa. Overall, this work demonstrates that coal can be effectively utilized to markedly amplify the mesophase pitch and carbon fiber yield from fluid catalytic cracking decant oil by relatively simple processing, while conserving utility as a precursor to high performance carbon fiber and potentially other high value graphitic products. [Display omitted] • Mild direct coal liquefaction in decant oil was used to obtain a coal extract. • The coal extract was thermally converted to a spinnable mesophase pitch. • Coal utilization improved yield to mesophase pitch nearly twofold. • Coal extract-derived carbon fiber displayed high modulus (>400 GPa). • Coal utilization resulted in a ∼70 % increase in yield to carbon fiber. [ABSTRACT FROM AUTHOR]