Effect of Shear Deformation and Temperature History on Crystal Transformation of Polyvinylidene Fluoride/Silica Composites: A Molecular Dynamics Study

ABSTRACT Polyvinylidene fluoride (PVDF) is increasingly utilized in various applications as a highly non‐reactive thermoplastic fluoropolymer. Combining nanofillers with PVDF is a common approach to enhance its properties. In this paper, molecular dynamics simulation is used to investigate the effect of shear and temperature history on the crystal transformation of the PVDF/SiO ₂ composite system. Polymer nanocomposites (PNCs) with different particle sizes of nano‐SiO ₂ fillers were designed and investigated. The interaction energy, mean square displacement, radial distribution function, and dihedral angle distribution were discussed. The results show that the interaction energy between PVDF and SiO ₂ increases with increasing filler particle size. The addition of nano‐SiO ₂ reduces the mobility of the PVDF molecular chains. The change of the system from 500 K to 440 K throughout 200 ps does not induce the crystal transformation in PVDF. Furthermore, this study demonstrates that both shear deformation and nano‐SiO ₂ contribute to inducing a conformational shift from gauche to trans, which promotes β‐phase formation. In conclusion, this study provides valuable insights into the microstructural and molecular dynamics characteristics of PNCs at the molecular level, supplying theoretical guidance and technical support for designing high‐performance PVDF/SiO ₂ composites.