Spectroscopic Analysis on Polyethylene Oxide Loaded with Fullerenes*

A broad spectroscopic investigation to better understand the structure and interactions between polyethylene oxide (PEO) and fullerenes (C60) is reported. PEO-C60 nanocomposites (PEO-C60NC) were obtained by dissolving PEO and C60 in water, mixing, and homogenization these dispersions by stirring, and water evaporation. This path exploited the insolubility of C60 in water, thus resulting in a standard polymer nanocomposite. The molecular dispersion of C60 in PEO (PEO-C60MD) was obtained by dissolving PEO and C60 in a common solvent (toluene, chloroform), mixing the two solutions, and evaporating the solvent. The outcome was a polymer within which C60 is molecularly dispersed, (PEO-C60MD). PEO-C60NC and PEO-C60MD containing various weight fractions of C60 were prepared.

Spectroscopic studies by X-ray diffraction (using a Bruker Discovery 8 spectrometer), Raman spectroscopy (using a Renishaw InVia Raman confocal microscope operating at 785 nm), FTIR (using a Bruker Tensor 27 coupled with a Hyperion FTIR confocal microscope), UV-Vis spectroscopy, and Electron Spin Resonance (using an EPR Elexsys spectrometer operating in the X-band) have been carried out on both PEO-C60MD and PEO-C60NC.

The modifications of the structural properties of PEO upon the addition of C60, either as a nanofiller or as a molecularly dispersed component, are investigated and reported in detail, with emphasis on the differences between the nanocomposite and the molecularly dispersed sample.