▎ 摘 要
NOVELTY - Treated carbon nanotube powder is mixed with aqueous solution of graphene oxide, stirred and ultrasonically-treated, to obtain dispersed phase solution. Using an injection syringe pump the dispersed phase solution from syringe (a) and dimethicone from syringe (b) are supplied to polypropylene-made system, to obtain droplets of graphene oxide/carbon nanotube composite beads. The droplets of beads are cured, washed, dried and carbonized to obtain three-dimensional graphene/carbon nanotube composite beads. USE - Preparation of three-dimensional graphene/carbon nanotube composite beads (claimed). ADVANTAGE - The method efficiently and economically provides three-dimensional graphene/carbon nanotube composite beads. DETAILED DESCRIPTION - Carbon nanotubes are immersed in mixed acid and refluxed at 80-85 degrees C for 2-3 hours, dialyzed after centrifuging, washed, and then dried in an oven at 60-70 degrees C to obtain treated carbon nanotube powder. The volume ratio of carbon nanotubes and mixed acid is 1:90-100. The mixed acid includes 65 %mass concentrated nitric acid and 98 %mass concentrated sulfuric acid in volume ratio of 1:2-4. The treated carbon nanotube powder is mixed with aqueous solution of graphene oxide, stirred at speed of 300-400 rpm and ultrasonically-treated with ultrasonic frequency of 40-50 KHz for 5-10 hours, to obtain dispersed phase solution. The solid content of graphene in aqueous solution is 1-1.5%. The ratio of content of carbon nanotube powder and graphene is 1:0.01-0.5. The dispersed phase solution i poured into syringe (a), and dimethicone is poured into syringe (b). Using an injection syringe pump the dispersed phase solution from syringe (a) and dimethicone from syringe (b) are supplied to polypropylene-made system, to obtain droplets of graphene oxide/carbon nanotube composite beads. The syringes (a) and (b) are connected to one end of polytetrafluoroethylene (PTFE) tube. The other end of the PTFE tube is connected to the system. The volume ratio of dispersed phase and dimethicone is 1:5-20. The droplets of beads are cured at 60-70 degrees C for 12-24 hours, washed with n-hexane for 4-6 times, and then dried in an oven at 140-160 degrees C for 6-9 hours and pre-oxidized at 270-290 degrees C for 1.5-2 hours. The beads are then carbonized from room temperature to 700-800 degrees C for 1.5-2.5 hours at heating rate of 4-6 degrees C/minute under nitrogen atmosphere to obtain three-dimensional graphene/carbon nanotube composite beads.