▎ 摘　　要

NOVELTY - A graphene oxide/polyimide porous composite film comprises a fluorine-free polyimide flat film substrate, and a fluorine-containing polyimide oxide porous film attached to the flat film substrate. USE - The graphene oxide/polyimide porous composite film is useful as insulating material in microelectronic application, especially in environment with humidity higher than 75% (claimed). ADVANTAGE - The graphene oxide/polyimide composite film can be prepared by a method, which does not cause pollution, is simple, convenient, non-toxic and low in cost, and successfully combines graphene oxide, polyimide and porous structure, thus achieving the reduction of the dielectric constant and the improvement of the mechanical properties of the polyimide film. The porous structure uses water drops as templates, which are volatile, easy to obtain, cheap and environmentally-friendly, so that no additional template removing step is required, the use of strong acid or strong alkali etching agent is not involved, and the incomplete template removing phenomenon is avoided. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the graphene oxide/polyimide porous composite film, which involves: (1) dispersing graphene oxide in deionized water to prepare a graphene oxide aqueous solution; (2) dissolving a surfactant in an organic solvent to prepare a surfactant organic solution; (3) mixing the graphene oxide aqueous solution with the surfactant organic solution, and stirring to prepare a graphene oxide-containing composite; (4) dissolving the graphene oxide-containing composite and fluorine-containing polyimide in an organic solvent to prepare a graphene oxide/polyimide organic solution; and (5) pouring the graphene oxide/polyimide organic solution on the fluorine-free polyimide flat film under high humidity.