Scanning Electron Microscopy and Raman Spectroscopy Characterization of Structural Changes Induced by Thermal Treatment in Innovative Bio-Based Polyamide Nanocomposites

Abstract

A comprehensive Raman scattering-based characterization of a full bio-based polyamide loaded with graphene nanoplatelets or layered double hydroxides (LDH) was assessed. The potential of the Raman spectroscopy was used to reveal several particularities of the nanocomposite structures induced by thermal treatment. Thus, a complete morpho-structural picture was obtained in combination with scanning electron microscopy (SEM) analysis of the neat polyamide and polyamide nanocomposites exposed at different thermal conditions (room temperature, 80 °C, and 145 °C). The analysis of G, D and 2D Raman peaks and their relative intensity ratio ID/IG, revealed the fact that the presence of graphene in polyamide is suitable for improving the essential physical properties and is also responsible for the decrease in the defects’ occurrence in the graphene layers. The surface of nanocomposites based on full bio-based polyamide, with different 2D fillers (graphenic and non-graphenic structures), was carefully evaluated before and after the thermal treatment by employing SEM and Raman analyses. The two thermal treatments allowed different chain mobility of the polymer (first temperature being over the polymer Tg and second one close to the melting phase in the viscoelastic stage). The spectroscopic and microscopic investigation was used to determine the conformational changes in filler aggregates and polymer surface, respectively.

Triazine and Fused Thiophene-Based Donor-Acceptor Type Semiconducting Conjugated Polymer for Enhanced Visible-Light-Induced H2 Production

“…The bands at 3067 cm −1 of PhIN-CPP and 3061 cm −1 of ThIN-CPP were related to the O–H backbone stretching vibration [ 42 ]. Moreover, other Raman bands located in between the wavenumbers ranging from 1450 cm −1 –850 cm −1 for both PhIN-CPP and ThIN-CPP were assigned to the bending, stretching, and deformation vibrations of C-C bonds and the rocking vibration in the CH 2 group [ 43 ]. Additionally, the bands at 1487 cm −1 of PhIN-CPP and 1495 cm −1 of ThIN-CPP were related to the C–H in plane vibration.…”