Spectroscopic Investigations of PEO Based Polymers and Nanofibers*

Polyethylene oxide (PEO) is a special polymer, soluble in both water and some organic solvents (such as chloroform). Fullerenes are not soluble in water but are soluble in chloroform. These features have been exploited in the study of the effect of solvent and nanofiller nature on the morphology and crystalline structure of PEO. Both “bulk” samples and mats of PEO nanofibers obtained by force spinning from solutions of PEO in water or chloroform have been investigated by spectroscopic techniques (Raman, UV-VIS, X-Ray diffraction). X-Ray investigations were focused on the crystallites’ size, the unit crystal parameters, and potential stress effects as revealed by the dependence of the X-Ray line position and width on the spinning rate, PEO concentration in the solvent, and Sn load. Additional information regarding crystalline phases and the mechanical stresses/strains in PEO polymers and mats of nanofibers have been obtained by Raman spectroscopy, using as excitation both a green (583 nm) and a red (785 nm) laser. The dependence of the position of Raman lines on spinning rate and nanofiller concentratios investigated in detail.