▎ 摘　　要

NOVELTY - Ultralight randomly oriented pure graphene aerogel film comprises 0.1-1.0 gm/cm3 dense film that are mutually overlapped by pi - pi conjugated bond with holes between the adjacent graphene sheets and the holes are consistent in all the directions. The graphene sheet has layered structure which are constructed by mutual overlapping of pi - pi conjugated bond. The layered structure of the graphene has 1-4 layers of plane oriented graphene sheet that has size greater than or equal to 100 mu m by pi - pi conjugate overlapping. USE - Ultralight randomly oriented pure graphene aerogel film. ADVANTAGE - Ultralight randomly oriented pure graphene aerogel film consumes less energy, protects environment, is simple to prepare and applied for high efficiency electromagnetic shielding and flexible thermal conduction. DETAILED DESCRIPTION - Ultralight randomly oriented pure graphene aerogel film comprises 0.1-1.0 gm/cm3 dense film that are mutually overlapped by pi - pi conjugated bond with holes between the adjacent graphene sheets and the holes are consistent in all the directions. The graphene sheet has layered structure which are constructed by mutual overlapping of pi - pi conjugated bond. The layered structure of the graphene has 1-4 layers of plane oriented graphene sheet that has size greater than or equal to 100 mu m by pi - pi conjugate overlapping. The layered structure of the graphene has 1-5 or more layers of plane oriented graphene sheet that has size greater than or equal to 100 mu m by pi - pi conjugate overlapping. The defect in the graphene sheet is represented by ID/TG which is less than or equal to 0.01. INDEPENDENT CLAIMS are included for: (1) a method for preparing ultralight randomly oriented pure graphene aerogel film which involves utilizing graphene oxide of average size greater than or equal to 100 mu m to prepare concentration of 20 mg/ml aqueous graphene oxide solution; (2) stirring the mixture in coagulating liquid or liquid nitrogen for 10-100 seconds to obtain graphene oxide gel film; (3) refrigerating the gel film at (-4)-20 degrees C for 1-12 hours or rapid freezing in liquid nitrogen; (4) placing the frozen thin film in high temperature furnace to carry out high temperature heat treatment in which the film is heated under inert gas atmosphere first at 400 degrees C with a heating speed of 0.1-4 degrees C/minute and keeping the temperature for 0.5-1 hours, then raising the temperature with a speed of 2-4 degrees C/minute to 1300 degrees C and keeping the temperature 1-4 hours, then again raising the temperature with a speed of 2-4 degrees C/minute to 3000 degrees C and keeping the temperature for 1-2 hours to obtain continuous ultra-pure random orientation of graphene aerogel film; (5) a method for preparing graphene oxide of average size greater than or equal to 100 mu m which involves using modified-Hummer method to obtain diluted graphite oxide solution and filtering the solution through a 140 mesh sieve to obtain the graphite oxide sheet; (6) mixing the obtained product in ice water according to volume ratio 1:10 and allowing the solution to stand for 2 hours; (7) adding hydrogen peroxide dropwise where, hydrogen peroxide has mass fraction of 30 wt.%; (8) mixing the solution until the mixture stops changing color which shows that the potassium permanganate has been completely removed from the liquid; (9) adding dropwise concentrated hydrochloric acid in 12 mole/l concentration into the obtained mixture until the flocculent graphite oxide disappears and filtering the obtained solution through the 140 mesh sieve to obtain graphite oxide wafer; and (10) placing the graphite oxide wafer on a shaker and washing the components with a stirring speed of 20-80 revolutions/minute to peel of the large pieces of graphite oxide wafer of average size greater than 100 mu m and distribution coefficient between 0.2-0.5.