Chemical fingerprinting of polyvinyl acetate and polycarbonate using electron energy-loss spectroscopy

Abstract

Accurate characterization of technologically relevant materials, particularly through spectroscopic techniques, necessitates the availability of reference information. However for electron energy-loss spectroscopy (EELS), reference spectra in the form of chemical fingerprints of even common polymers are not readily available. Here, the chemical fingerprints of polymers, which have been generated through EELS, can be used for the identification and compositional analysis of polymeric materials by chemical bond mapping with nanoscale spatial resolution. Electron energy-loss spectra of polyvinyl acetate (PVAc) and polycarbonate (PC), including the low-loss region and core-loss edges of carbon and oxygen, are reported. Additionally, decomposition of the carbon K-edge fine-structure of both polymers was performed and the observed peaks were assigned to bonding transitions. The carbon K-edge from low energy resolution spectra was also analyzed to address the challenges associated with the processing of easily available low energy resolution EELS data. This work demonstrates the high sensitivity of EELS towards identification of changes in the chemical structure of polymeric materials, which highlights its potential for wider applicability in polymer science.