▎ 摘　　要

Transparent polyimide (PI) and chemically modified graphene nanocomposite films are prepared from solutions of pyromellitic dianhydride (PMDA)/4,4'-oxydianiline (ODA) poly(amic acid) with various amounts (0.20.8?wt%) of graphene carboxylic acid (GCA) in DMAc. The GCA is synthesized by modifying chemically oxidized graphene (COG) with many carboxylic acid groups (COOH) and is well-dispersed in DMAc, the organic solvent most frequently used for PI synthesis. The GCA sheets in the PI/GCA composite films are well-dispersed and aligned two-dimensionally in the direction parallel to the PI films, which enhances the mechanical properties of the nanocomposite films.