▎ 摘　　要

NOVELTY - Manufacturing composite sample involves: (a) mixing cellulose acetate, graphene and acetone in a volume ratio of 1:1:3-1:1:5 to obtain a gel liquid; (b) subjecting the samples to polishing, corroding, rinsing and blow-drying according to the metallographic sample preparation to obtain metallographic samples with corrosion surface; (c) evenly coating the gel liquid on the samples with corrosion surface and then leaving until the gel liquid dries naturally into a gel film; (d) peeling off the film from the sample, then spraying carbon on the effective surface of the film in a vacuum coating device to get a composite film, and contacting the effective surface with the corrosion surface before the peeling; and (e) soaking the composite film in acetone until it is curled, taking out with a carrier net and drying to obtain a carbon film. USE - The method is useful for manufacturing composite sample for transmission electron microscope detection. ADVANTAGE - The method solves the bubble problem and the problem of residual contaminants on the composite sample, and improves efficiency, success rate and quality of the composite sample. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a gel liquid, which is prepared by mixing cellulose acetate, graphene and acetone; and (2) application method of the gel liquid, which involves the steps (b)-(e) as per above se.