Mechanical Characterization of Polymer Nanocomposite Films: Influence of Force Regimes and Nano Silica Reinforcement

Kandemir A. Ç.

POLYMER COMPOSITES, cilt.46, sa.15, ss.14447-14460, 2025 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 46 Sayı: 15
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1002/pc.30072
  • Dergi Adı: POLYMER COMPOSITES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Sayfa Sayıları: ss.14447-14460
  • Anahtar Kelimeler: atomic force microscopy, biocompatible, coating, colloidal probe microscopy, instrumented indentation, mechanical properties, nanocomposite
  • TED Üniversitesi Adresli: Evet

Özet

This study examines the mechanical properties of biocompatible nanocomposite films composed of polyvinylpyrrolidone (PVP) reinforced with nano silica particles (NSPs), focusing on the influence of diverse force regimes. Colloidal probe microscopy (CPM) and instrumented indentation were used to assess mechanical behavior, revealing a force-dependent variation in elastic modulus. CPM measurements at microNewton-level forces yielded moduli in the MPa range, while instrumented indentation at milliNewton-level forces resulted in moduli in the GPa range, indicating a stiffer response. This variation is likely due to polymer flow behavior under different force regimes, where lower forces enhance compliance, whereas higher forces restrict material flow, increasing stiffness. Structural characterization via AFM and TEM confirmed homogeneous NSP dispersion at lower concentrations (1 and 3 wt%), while higher loadings (5 wt% and beyond) caused agglomeration and increased surface roughness. Theoretical models (Einstein, Guth, Kerner, and Mooney) underestimated reinforcement at low NSP volume fractions, suggesting that localized particle accumulation beneath the indentation tips enhances stiffness beyond model predictions. This discrepancy emphasizes the importance of real-world particle distribution and stress localization in nanocomposite films. These findings are particularly relevant for biomedical applications, where surface interactions and mechanical stability are critical.