Study of Nonisothermal Crystallization Kinetics of Unstretched and Uniaxially Stretched Electroactive PVDF Composite Films

Abstract

Incorporation of graphene‐based fillers such as graphene oxide (GO) and reduced graphene oxide (rGO) into polyvinylidene fluoride (PVDF) followed by uniaxial stretching can significantly improve their electroactive phase content as well as the dielectric properties. In this study, the nonisothermal crystallization kinetics of unstretched and uniaxially stretched PVDF‐GO and PVDF‐rGO composite films are investigated through differential scanning calorimetry (DSC) at different cooling rates. Avrami‐modified Jeziorney's model is used to understand their crystallization behavior which leads to the nucleation of electroactive crystalline phases in PVDF. Avrami's exponent “n” values in the range of 2–4 are obtained for nonisothermal crystallization of PVDF in different samples which reveal both two‐ and three‐dimensional growth of spherulites in the crystalline region. Kissinger's method is used to calculate the activation energy of crystallization and the results reveal accelerated crystallization of PVDF after addition of GO and rGO fillers followed by uniaxial stretching.

Recent progress in piezoelectric thin films as self-powered devices: material and application

“…There are several ways to make PVDF films, such as electrostatic spinning, solution casting, solution casting, spin coating method, electro-spinning technique, stretching, vacuum evaporation, and homogenization, etc (Jin et al, 2021;Yen et al, 2022;Das et al, 2023;Ghosh et al, 2023;Mishra et al, 2023;Sarkar et al, 2024). The scratch spraying method was used to make polyvinylidene fluoride-trifluoro ethylene (PVDF-TrFE) copolymers (Singh et al, 2018;Bhunia et al, 2019;Sapkota et al, 2022).…”