POS9-0508
Surface Defect Repair of Recycled Carbon Fibers Using Carbon Dots for Composite Applications
Topic
S9. Polymer Technology for Sustainability
When and Where
Sep 30, 2026
08:30 - 09:30
Room 301 (Grand Ballroom)
Session Chairs
Heesuk KIM
Jinhye BAE
Presenter(s)
Donguk Kim (Ulsan National Institute of Science and Technology)
Co-Author(s)
Abstract
Along with the growing concern about climate change and environmental pollution, the demand for recycled materials has been growing. Accordingly, research on carbon fiber recycling and recycled carbon fibers is actively being conducted. Carbon fiber is the material that is widely used in carbon fiber reinforced composites, which have high mechanical properties. However, recycled carbon fibers are often damaged by extreme atmosphere during the recycling process. The damage induces stress concentration under loading, deteriorates the mechanical properties of recycled carbon fiber, and consequently limits the application to the composites. Therefore, this study aims to make the recycled carbon fiber applicable to composites by restoring the mechanical properties of recycled carbon fiber through the repair of surface defects with carbon dots.
In this study, commercial carbon fibers were pyrolyzed in the furnace to mimic the recycling process. Carbon dots were synthesized using citric acid and urea through a thermal degradation method. Carbon dot solutions were prepared using distilled water as a solvent. Solutions underwent filtering and dialysis to remove the impurities. Recycled carbon fibers were dip-coated with the carbon dot solutions and dried.
Synthesized carbon dots were characterized by a transmission electron microscope. A single-fiber tensile test was conducted to evaluate the effect of carbon dots on the tensile properties of recycled carbon fibers. Contact angle analysis was also conducted to compare the wettability of the fibers, thereby indirectly comparing the applicability on composites. As a result, the tensile property of recycled carbon fiber was improved after carbon dot treatment, while maintaining the wettability. Various material characterization techniques were conducted to explain the property enhancement. This result suggests that the recycled carbon fiber can be applied to composites with proper post-treatment.
In this study, commercial carbon fibers were pyrolyzed in the furnace to mimic the recycling process. Carbon dots were synthesized using citric acid and urea through a thermal degradation method. Carbon dot solutions were prepared using distilled water as a solvent. Solutions underwent filtering and dialysis to remove the impurities. Recycled carbon fibers were dip-coated with the carbon dot solutions and dried.
Synthesized carbon dots were characterized by a transmission electron microscope. A single-fiber tensile test was conducted to evaluate the effect of carbon dots on the tensile properties of recycled carbon fibers. Contact angle analysis was also conducted to compare the wettability of the fibers, thereby indirectly comparing the applicability on composites. As a result, the tensile property of recycled carbon fiber was improved after carbon dot treatment, while maintaining the wettability. Various material characterization techniques were conducted to explain the property enhancement. This result suggests that the recycled carbon fiber can be applied to composites with proper post-treatment.
