▎ 摘　　要

NOVELTY - Graphene-doped silicon carbide core-shell composite polyimide permeable membrane is a film composed of graphene-doped silicon carbide core-shell structure and polyimide resin gel, where after the graphene-doped silicon carbide core-shell structure is epitaxially grown by chemical vapor deposition from the doped silicon carbide substrate, and is formed by selectively etching the heavily doped silicon carbide layer in the electrochemical etching method. USE - The permeable membrane is used in applications including high-salt, oxygen-enriched, and low-salt raw water treatment. ADVANTAGE - The permeable membrane has greatly improved desalination rate and pollution resistance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a preparation method of the graphene-doped silicon carbide core-shell composite polyimide permeable membrane, involving (a) preparation of silicon carbide-n-silicon carbide-graphene composite material by taking the clean silicon carbide substrate, putting it into the metal organic chemical vapor deposition (MOCVD) furnace, after reducing the vacuum degree of the chamber to below 5x10-5 Pa, continuously introducing hydrogen, controlling the hydrogen flow rate to be 5-10L/minute, after setting the gradient heating program to gradually increase the temperature in the chamber to 1600degrees Celsius, passing 5-10 ml/minute of silane gas and 2-5 ml/minute of propane gas to generate a new silicon carbide surface on the surface of the silicon carbide substrate, then gradually lowering the temperature in the chamber to 640-660degrees Celsius, injecting nitrogen plasma for doping, forming a heavily doped n-silicon carbide layer on the silicon carbide substrate, raising the temperature in the chamber to 1000degrees Celsius, introducing argon gas to form argon plasma, controlling the flow rate of argon gas to keep at 1-2 L/minute, resetting the gradient heating program to gradually increase the temperature in the chamber to 1600degrees Celsius, after completing the procedure, naturally cooling the chamber to room temperature, and restoring the air pressure in the chamber to normal pressure to obtain a silicon carbide-n-silicon carbide-graphene composite material, (b) preparation of graphene-doped silicon carbide core-shell structure by performing UV lithography on the silicon carbide-n silicon carbide-graphene composite material obtained in step (a), forming an array-like stripe structure with a stripe width of 800-900 nm, then placing the composite material after UV lithography in an electrolyte solution, applying a constant voltage of 15-18 V for electrochemical corrosion, and reacting for 10-20 minutes to obtain a graphene-doped silicon carbide core-shell structure, and (c) preparation of graphene-doped silicon carbide composite polyimide matrix film by weighing the polyimide resin gel, putting it into the mold, putting the graphene-doped silicon carbide core-shell structure obtained in step (b), putting the mold into the MOCVD furnace, feeding methane gas and argon gas into the chamber to form argon plasma, where the initial vacuum degree of the control chamber is 5000 Pa, controlling the gas flow rate at 0.1-0.5 ml/minute, setting the gradient heating program to gradually increase the temperature in the chamber to 400-450degrees Celsius, after completing the procedure, naturally cooling the chamber to room temperature, and restoring the air pressure in the chamber to normal pressure to obtain the precursor of graphene-doped silicon carbide core-shell composite polyimide resin, then gradually reducing the vacuum degree of the chamber to 200-1000 Pa, resetting the gradient heating program to gradually increase the temperature in the chamber to 100-300degrees Celsius, naturally cooling the chamber after completing the program, when the temperature of the chamber drops to 50-100degrees Celsius, the film is unloaded from the mold, the obtained graphene-doped silicon carbide composite polyimide matrix membrane material is the graphene-doped silicon carbide core-shell composite polyimide permeable membrane.