Amino Functionalization of Graphite Nanoplatelet

Graphite nanoplatelet has been widely used as a low-cost filler for conducting polymer nanocomposites. To improve the compatibility and interfacial interactions with polymer matrix, graphite nanoplatelets were surface treated by two amino-functionalization agents which were triethylenetetramine and ammonium bicarbonate. Two different dispersion techniques, including ultrasonication and magnetic stirring, were applied to further promote the functionalization process. Several characterization tools were employed to determine the surface chemistry of graphite nanoplatelets before and after functionalization, as well as to characterize the effects of ultrasonication on the aspect ratio of graphite nanoplatelets. Amine and amide functional groups were identified to be present on the functionalized graphite nanoplatelets. The triethylenetetramine treated graphite nanoplatelets surface exhibited much higher nitrogen content along with more prominent functional groups than the ammonium bicarbonate treated one. This result is consistent with the higher relative intensities of D bands in Raman spectra as a reflection of a greater degree of disorder for the triethylenetetramine treated graphite nanoplatelets. The suspension stability of graphite nanoplatelets dispersion was significantly improved after functionalization, in particular for the triethylenetetramine treated one.