PANI–WO3·2H2O Nanocomposite: Phase Interaction and Evaluation of Electronic Properties by Combined Experimental Techniques and Ab-Initio Calculation

Abstract

The development of conjugated polymer-based nanocomposites by adding metallic particles into the polymerization medium allows the proposition of novel materials presenting improved electrical and optical properties. Polyaniline Emeraldine-salt form (ES–PANI) has been extensively studied due to its controllable electrical conductivity and oxidation states. On the other hand, tungsten oxide (WO3) and its di-hydrated phases, such as WO3·2H2O, have been reported as important materials in photocatalysis and sensors. Herein, the WO3·2H2O phase was directly obtained during the in-situ polymerization of aniline hydrochloride from metallic tungsten (W), allowing the formation of hybrid nanocomposites based on its full oxidation into WO3·2H2O. The developed ES–PANI–WO3·2H2O nanocomposites were successfully characterized using experimental techniques combined with Density Functional Theory (DFT). The formation of WO3·2H2O was clearly verified after two hours of synthesis (PW2 nanocomposite), allowing the confirmation of purely physical interaction between matrix and reinforcement. As a result, increased electrical conductivity was verified in the PW2 nanocomposite: the DFT calculations revealed a charge transfer from the p-orbitals of the polymeric phase to the d-orbitals of the oxide phase, resulting in higher conductivity when compared to the pure ES–PANI.

Virus adsorbent systems based on Amazon holocellulose and nanomaterials

“…The vibrational bands at 1295, 1240, and 1120 cm −1 were assigned, respectively, to the stretching of the CN + bond of the bipolaronic structure and the NH + bond referring to delocalized electrons due to protonation doping. Also, at 800 cm −1 is the out‐of‐plane deformation of the CH bonds of the benzenoid rings (de Souza Carolino et al, 2022). The ratio between the areas of the quinoid and benzenoid (Q/B) bands (1560 and 1462 cm −1 , respectively) was useful to estimate the doping level of ES‐PANI.…”

“…is the out-of-plane deformation of the C H bonds of the benzenoid rings (de Souza Carolino et al, 2022). The ratio between the areas of the quinoid and benzenoid (Q/B) bands (1560 and 1462 cm À1 , respectively) was useful to estimate the doping level of ES-PANI.…”