▎ 摘　　要

NOVELTY - Preparation of high-performance mesophase asphalt-based graphite fiber involves dispersing nitrogen-doped graphene quantum dots in quinoline, ultrasonically stirring for 0.5-2 hours under vacuum, adding mesophase asphalt, stirring in a mixed inert atmosphere at 280-350 degrees C for 1-5 hours, spinning into a mesophase asphalt fiber having diameter of 10-20 mu m at 280-350 degrees C, heating the mesophase asphalt fiber from room temperature to 240-300 degrees C in an oxidizing atmosphere, performing pre-oxidation treatment at 0.5-3 degrees C/minute, carbonizing at 500-700 degrees C and 5-15 degrees C/minute under an inert atmosphere, and performing graphitization treatment under nitrogen atmosphere at 2400-2800 degrees C with draw ratio of 1.01-1.12 and filament speed of 1-10 m/minute. The concentration of nitrogen-doped graphene quantum dots in quinoline is 0.1-5 g/L. USE - Preparation of high-performance mesophase asphalt-based graphite fiber used as reinforcement for robotic arms. ADVANTAGE - The method enables preparation of high-performance mesophase asphalt-based graphite fiber with modulus of 800-950 GPa and strength of 2.6-3.5GPa. The high-performance mesophase asphalt-based graphite fiber interface has a radial structure with no clefts. DETAILED DESCRIPTION - Preparation of high-performance mesophase asphalt-based graphite fiber involves dispersing nitrogen-doped graphene quantum dots in quinoline, ultrasonically stirring for 0.5-2 hours under vacuum, adding mesophase asphalt, stirring in a mixed inert atmosphere at 280-350 degrees C for 1-5 hours, spinning into a mesophase asphalt fiber having diameter of 10-20 mu m at 280-350 degrees C, heating the mesophase asphalt fiber from room temperature to 240-300 degrees C in an oxidizing atmosphere, performing pre-oxidation treatment at 0.5-3 degrees C/minute, carbonizing at 500-700 degrees C and 5-15 degrees C/minute under an inert atmosphere, and performing graphitization treatment under nitrogen atmosphere at 2400-2800 degrees C with draw ratio of 1.01-1.12 and filament speed of 1-10 m/minute. The concentration of nitrogen-doped graphene quantum dots in quinoline is 0.1-5 g/L. The nitrogen-doped graphene quantum dots are prepared by potentiostatic electrolysis at a voltage of 1-5 V and current intensity of 0.05-0.2 mA for 1-3 hours, using 1-10 mol/L aqueous ammonia solution as an electrolyte, filtering through a 10-nm microfiltration membrane, washing the filtrate with deionized water, and vacuum-drying. An anode of the electrolysis system is a high-purity graphite rod, and a cathode of the electrolysis system is a platinum electrode. The nitrogen-doped graphene quantum dots have particle diameter of 2-10 nm.