Investigation on Relaxational Behavior of Alkylammonium Ions Intercalated in Graphite Oxide

Graphite oxide (GO) nanocomposites have been synthesized to contain various concentrations of intercalated alkylammonium ions and characterized with X-ray diffraction, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and differential scanning calorimetry. Depending on their concentration, the alkyl chains may lie parallel to the GO plane one or two layers thick or they form two columns inclined at an angle ∼37° to the plane. Dielectric spectroscopy reveals a relaxation process far below room temperature, attributed to small-angle wobbling around the long molecular axis. The activation energy of this relaxation increases as the intercalate changes from one to two layers, and to dual columns, with increasing interactions among the intercalated molecules. An additional phase transition occurs in composites with high concentrations of intercalate between a rotator-type solid phase to a disordered phase for the confined alkyl chains