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<p>This study systematically investigates hexavalent chromium oxide (CrO₃) doping at 0.2, 0.4, and 0.6 wt.% on PVA/PEO nanocomposites. X-ray diffraction identifies semi-crystalline peaks in pure PVA at 2<i>θ</i> = 19.6°, 22.7°, and 40.5°, and in PEO at 13.3° and 21.4°; the blend shows peaks at 19.25° and 23.49°, indicating hydrogen-bond miscibility. CrO<sub>3</sub> broadens/reduces intensities, enhancing amorphicity via nanoparticle intercalation. FT-IR spectroscopy detects O–H stretching (3012–3670 cm<sup>−1</sup>), C-H (2905 cm<sup>−1</sup>), C = O (1733 cm<sup>−1</sup>), and C–O–C (1145–1062 cm<sup>−1</sup>) in a pure blend. Doping yields Cr–O vibrations (603–528 cm<sup>−1</sup>), modifies O–H/C-H, and confirms physical interactions and chain restriction. UV–Visible spectra show heightened absorption/redshift (220–400 nm) with CrO<sub>3</sub>, narrowing bandgap to ~ 3.2 eV via charge-transfer complexes. Thermogravimetric analysis (TGA) unveils delayed three-stage decomposition water loss (&lt; 150 °C), dehydroxylation (250–300 C), rupture (&gt; 400 C) with ~ 25 wt.% residue at 600 °C for 0.6 wt.%). AC electrical studies (0.1 Hz to 7 MHz) exhibit ε′ &gt; 5 × 10<sup>4</sup> at 0.1 Hz (optimal 0.4 wt.%) and a drop in loss (Maxwell–Wagner-Sillars). DC conductivity ~ 10<sup>−8</sup> S/cm arises from hopping; Cole–Cole (M′ vs M″) plots display semicircles/Warburg tails peaking at 0.4 wt.% CrO<sub>3</sub>.</p>

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Multifunctional nanocomposites based on a PVA/PEO matrix loaded with CrO3: Structural, optical, morphological, thermal, and electrical characterization

  • 期刊论文

  • 发表日期：

    2026年5月13日

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  • N. F. Aref,
  • S. M. Metawea,
  • E. T. Elsherbiney,
  • M. M. Naseem,
  • A. A. Menazea,
  • A. M. Abdelghany,
  • I. S. Elashmawi

摘要

This study systematically investigates hexavalent chromium oxide (CrO₃) doping at 0.2, 0.4, and 0.6 wt.% on PVA/PEO nanocomposites. X-ray diffraction identifies semi-crystalline peaks in pure PVA at 2θ = 19.6°, 22.7°, and 40.5°, and in PEO at 13.3° and 21.4°; the blend shows peaks at 19.25° and 23.49°, indicating hydrogen-bond miscibility. CrO3 broadens/reduces intensities, enhancing amorphicity via nanoparticle intercalation. FT-IR spectroscopy detects O–H stretching (3012–3670 cm−1), C-H (2905 cm−1), C = O (1733 cm−1), and C–O–C (1145–1062 cm−1) in a pure blend. Doping yields Cr–O vibrations (603–528 cm−1), modifies O–H/C-H, and confirms physical interactions and chain restriction. UV–Visible spectra show heightened absorption/redshift (220–400 nm) with CrO3, narrowing bandgap to ~ 3.2 eV via charge-transfer complexes. Thermogravimetric analysis (TGA) unveils delayed three-stage decomposition water loss (< 150 °C), dehydroxylation (250–300 C), rupture (> 400 C) with ~ 25 wt.% residue at 600 °C for 0.6 wt.%). AC electrical studies (0.1 Hz to 7 MHz) exhibit ε′ > 5 × 104 at 0.1 Hz (optimal 0.4 wt.%) and a drop in loss (Maxwell–Wagner-Sillars). DC conductivity ~ 10−8 S/cm arises from hopping; Cole–Cole (M′ vs M″) plots display semicircles/Warburg tails peaking at 0.4 wt.% CrO3.