▎ 摘　　要

Graphite oxide was prepared by oxidation of graphite using the Hummers method, and its ultrasonication in water yielded dispersed graphene oxide (GO) sheets. These sheets were then crosslinked with a water soluble polymer, namely poly (allylamine) hydrochloride (PAH), by carbodiimide coupling. Free standing composite films were obtained by filtration. These crosslinked composites showed better mechanical properties than unmodified GO films and those of composites that were made by simple mixing of GO and PAH. The filtration process was optimized to produce strong GO films which were subsequently crosslinked with PAH in-situ to produce very strong composites with tensile strengths up to 146 MPa. (C) 2010 Elsevier Ltd. All rights reserved.