Graphene oxide porous paper from amine-functionalized poly(glycidyl methacrylate)/graphene oxide core-shell microspheres

Various functional materials, such as metal nanoparticles, carbon nanotubes and conducting polymers were coated on polymer microspheres finding various uses in electronic and biomedical applications. Herein, we demonstrate that single graphene oxide (GO)sheets could be easily wrapped on amine-functionalized poly(glycidyl methacrylate)(PGMA-ed)microspheres (~2.5 µm in diameter)to form a PGMA-ed/GO core-shell structure with a thickness of ca. 50 nm. Subsequently, the synthesized GO-skin microspheres were consolidated by heating them to 60 °C to form a robust self-standing paper through the formation of electrostatic and van der Waals attractive forces between the very large surfaces of the GO, together with the formation of hydrogen bonding during the dewatering and drying processes, where the GO skins are interconnected to provide an electrical path and mechanical skeletal structure. When a stabilized GO dispersion was added to the PGMA-ed microspheres, the GO sheets were uniformly self-assembled on the PGMA-ed microsphere surfaces, seemingly through dipole-dipole interactions and amine-epoxide chemical reactions. This approach provides a simple route for the large volume production of PGMA-ed/GO core-shell microspheres and large-sized self-standing paper that may find various uses in optoelectronic device materials and porous membrane applications.