▎ 摘　　要

NOVELTY - Preparing graphene composite film comprises: (i) mixing graphite and strong oxidant, adding organic polymer flocculant polyacrylamide, stirring to obtain a graphite emulsion-I, passing through a sieve to obtain a graphite emulsion-II, passing ozone to obtain graphite emulsion-III, filtering to obtain graphite emulsion-IV; (ii) mixing the graphite emulsion-IV with ethanol solution, stirring; (iii) adding muddy water with graphite into a container, carrying out vacuum filtration; (iv) punching the graphene membrane-I; and (v) placing the graphene film-II between two graphene film-I and bonding. USE - The method is useful for preparing graphene composite film. ADVANTAGE - The graphene composite film has increased flexibility, small thickness difference and convenient subsequent processing of the membrane body. DETAILED DESCRIPTION - Preparing graphene composite film comprises: (i) mixing 10 pts. wt. graphite and 5 pts. wt. strong oxidant (85-98%) for 5-8 minutes, adding 1-3 pts. wt. organic polymer flocculant polyacrylamide, stirring for 20-30 minutes to obtain a graphite emulsion-I, passing the graphite emulsion-I through a sieve having a pore size of 0.1-0.3 mm to obtain a graphite emulsion-II, passing ozone into graphite emulsion-II, aerating and stirring for 10-20 minutes to obtain graphite emulsion-III, filtering the graphite emulsion-III via filter having a pore size of 0.1-0.3 mm to obtain graphite emulsion-IV; (ii) mixing the graphite emulsion-IV with 75-88% ethanol solution and clean water, stirring for 4-7 minutes, allowing it to stand for 20-30 minutes, dissolving polyacrylamide in ethanol solution, allowing it to stand, separating muddy water with graphite, drying in a chamber at 65-70 degrees C until moisture content of turbid water is 50-60%; (iii) adding muddy water with graphite into a container equipped with filter membrane, carrying out vacuum filtration with a vacuum degree of 0.03 to -0.1 MPa, filtering along the edge and stirring the container at a speed of 200-400 rotations/minute for 1-2 hours, uniformly distributing the graphene film on the filter of the container under the effect of centrifugal force, removing the filter and separating the graphene membrane-I from the filter; (iv) placing the graphene membrane-I in a punching machine, carrying out punching to form graphene film-II having a pore size of 0.1-0.25 mm and density of 80-100 round holes/cm3; and (v) placing the graphene film-II between the two graphene film-I, then bonding through liquid adhesive.