Novel PEG functionalized graphene nanosheets: enhancement of dispersibility and thermal stability.

A series of polyethylene glycol (PEG) functionalized graphene sheet hybrid materials (FGHMs) have been successfully synthesized via ester linkages. Interestingly, our products can be dispersed in both polar/protic solvents and nonpolar/nonprotic ones, which differ significantly from previously reported systems and are of great value in the wide-spread application of these "carbon nanosheet" based materials by solution-phase processing. Furthermore, the addition of PEG-modified carbon nanosheets as nanofillers significantly improves the thermal stability of the bulk polymers. In our case, an increase of 35 K in thermal stability can be obtained for PEG4000 after filling with as low as 1 wt % of the PEG modified carbon sheets, suggesting their great potential as novel nanofillers in industry.