Thermo-Active Behavior of Ethylene-Vinyl Acetate | Multiwall Carbon Nanotube Composites Examined by in Situ near-Edge X-ray Absorption Fine-Structure Spectroscopy.

NEXAFS spectroscopy was used to investigate the temperature dependence of thermally active ethylene-vinyl acetate | multiwall carbon nanotube (EVA|MWCNT) films. The data shows systematic variations of intensities with increasing temperature. Molecular orbital assignment of interplaying intensities identified the 1s → π* and 1s → π* transitions as the main actors during temperature variation. Furthermore, enhanced near-edge interplay was observed in prestrained composites. Because macroscopic observations confirmed enhanced thermal-mechanical actuation in prestrained composites, our findings suggest that the interplay of C=C and C=O π orbitals may be instrumental to actuation.