Physicochemical, Vibrational and EPR Spectral Analysis of Soot-Filled Polystyrene

Abstract

In this work, we investigate patterns of these materials and their composites with an emphasis on vibrational spectroscopy and electron paramagnetic resonance (EPR) response. Such soot in the polystyrene matrix leads to structural and electronic changes that are attractive for advanced material uses. Vibrational spectra, served as an atomic level probe to the molecular interactions in these composites, displaying small shifts in the absorption bands; characteristic of soot modification in the polymeric matrix. EPR spectroscopy supported the evidence of stable paramagnetic centers in the soot-filled polystyrene composites. These centres were found to be responsible for the broadening of the EPR signal, suggesting possible magneticlike behavior that may compete with classical magnetic materials. Elemental composition and bonding at the interface were also found to be composed of carbon, hydrogen, and oxygen by X-ray fluorescence analysis. Notably, the findings highlight that there is not a simple linear correspondence between soot content and the observed paramagnetic parameters implying that the interaction of soot distribution, interface bonding and defect types are more complex. These results provide new clues for the design of functional composites. In conclusion, the results contribute to our knowledge on the influence of carbonaceous fillers, such as soot, on polymer matrices. Possible applications are in advanced composites for electronics, sensing and magnetic materials, which could take advantage of novel structural and paramagnetic properties of soot-filled polymers. The present work provides insight into the multifunctional behavior of polymer−carbon composites and the necessity to study vibrational and EPR spectra together.