Chitosan‐functionalized graphene oxides (FGOCs) were successfully synthesized. FGOCs were found to significantly improve the solubility of the GO in aqueous acidic media. The presence of organic groups was confirmed by means of XPS and TGA. Restoration of the sp2 carbon network and exfoliation of graphene sheets were confirmed by Raman spectroscopy, UV‐visible spectroscopy and WAXD. The SEM and AFM investigations of the resultant FGOCs showed that most of the graphene sheets were individual and few were layered. Controlled release behavior of Ibuprofen and 5‐fluorouracil was then investigated. We found that FGOCs are a promising new material for biological and medical applications. magnified image

No abstract

Cover: The cover illustrates a rolled polyimide (PI)/graphene carboxylic acid (GCA) nanocomposite film. In the image, wrinkled graphene sheets are 2D‐aligned and well‐dispersed in a PI matrix with no covalent interaction, highlighted by the blue fluorescent bonds. The PI/GCA nanocomposite film may have application as a gas barrier, an anti‐corrosion material, or a flame retardant material. Further details can be found in the article by G. Y. Kim, M.‐C. Choi, D. Lee, and C.‐S. Ha* .

No abstract

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 (0.2–0.8 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.