Fig. 1: Mechanism and MD simulations of PVDF doped with anhydrous CaCl₂.

a Schematic representation of the random ion dipole alignment between PVDF polymer chains and Ca²⁺ ions in the absence of heat and electric field. b Ion-dipole interaction between PVDF polymer chains and Ca²⁺ ions and directional alignment of the dipoles in the presence of heat and electric field and (c) A zoom in view schematically represents the ion-dipole interaction between Ca²⁺ ions and F atoms, which induces an all-trans conformation and directional alignment of the dipoles. d Molecular dynamic simulation model using PVDF ‘mer’ chains and CaCl₂. e RDF results of Ca²⁺-F bonds with different CaCl₂ concentrations (0.5, 1.0, 2.0, and 4.0 wt.%). f RDF results of Ca and Cl bonds with H and F atoms, respectively, in PVDF chains with a CaCl₂ concentration of 1.0 wt.%. g Dihedral angles distribution of the PVDF chains ranging from 0° to 180°. Dihedral angles distribution of the PVDF chains near the (h) 60° (Gauche) and (i) 180° (Trans), respectively.