▎ 摘　　要

NOVELTY - Manufacturing a composite film comprises flushing cold water on a surface of a steel plate to remove grinding paste and oil and then washing using distilled water and propyl ketone, and drying the plate at 40-60 degrees C for 5-15 minutes; performing Hummers method for synthesizing graphene oxide suspension liquid and then centrifuging at 4000 revolutions per minute, and precipitating a solid metal substance and then drying the substance in a vacuum furnace to obtain graphene oxide; and adding 0.5-10 ml of silane, 1-40 ml of water and 1-90 ml of organic solvent in the graphene oxide. USE - The method is useful for manufacturing a composite film, which is useful for protecting a metal substrate from corrosion (claimed). ADVANTAGE - The compact composite film effectively protects the metal substrate from corrosion for long period of time. DETAILED DESCRIPTION - Manufacturing a composite film comprises flushing cold water on a surface of a steel plate to remove grinding paste and oil and then washing using distilled water and propyl ketone, and drying the plate at 40-60 degrees C for 5-15 minutes; performing Hummers method for synthesizing graphene oxide suspension liquid and then centrifuging at 4000 revolutions per minute, and precipitating a solid metal substance and then drying the substance in a vacuum furnace to obtain graphene oxide; adding 0.5-10 ml of silane, 1-40 ml of water and 1-90 ml of organic solvent in the graphene oxide in an electrolytic groove, and regulating pH value to 3-7 and then hydrolyzing at 25-40 degrees C for 24-48 hours and then uniformly stirring; selecting a traditional three-electrode system including a saturated calomel electrode (SCE) as a reference electrode, a molybdenum electrode as auxiliary electrode and a metal substrate as working electrode; applying a constant potential of -0.3 to -1 V/SCE on the plate for 1 minute; and depositing a substrate on the film under the presence of nitrogen and then putting into an air blast drying box at 80-150 degrees C, and solidifying the film for 30-90 minutes. The silane has a structural of formula (I) or formula (II). R = methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl or acetoxy; X = alkyl, alkenyl, amino, epoxy, mercapto-substituted alkyl or alkenyl, methoxy, ethoxy or benzyl; and Y1 = CH2CH2, (CH2)3-NH-(CH2)3, or (CH2)3-S4-(CH2)3.