Electron beam irradiation and carbon nanotubes influence on PVDF-PZT composites for energy harvesting and storage applications: Changes in dynamic-mechanical and dielectric properties

In this work, the PVDF-PZT composite was effectively manufactured using a solution-casting approach. The structural, dielectric, and dynamic-mechanical characteristics of PVDF-PZT are investigated as a function of electron beam (EB) dosage (10, 20, and 30 kGy) and CNT loading (0, 0.5, 1, and wt.%). Incorporating CNT into PVDF-PZT up to 1 wt% increases the storage modulus due to a strong interaction between the PVDF matrix and CNT. In a reverse manner, storage modulus and crosslinking density decrease with 10 and 20 kGy of EB, then slightly increase due to alteration of the internal structure of polymer composites. Due to enhanced charge carriers and forming new conductive pathways, the dielectric parameters dielectric constant (epsilon'), dielectric loss (epsilon ''), and ac conductivity (sigma ac) of PVDF-PZT rose with increasing CNT content. Both epsilon' and epsilon'' of PVDF-PZT also exhibited rising values with EB irradiation dose due to chain scission and structural rearrangements. A slight increase of sigma ac upon EB irradiation is also observed. Due to increased carrier mobility, the dielectric modulus (M') real part is decreased as CNT content and EB dosage grow. When CNT was added up to 1 wt%, the observed Maxwell-Wagner-Sillars polarization in the imaginary portion of the electric modulus (M '') curves moved to a higher frequency, attributed to an increase in charge carrier mobility. At-low-frequency region, M '' values are decreased with EB doses due to increased charge carrier mobility. These findings support using EB as a powerful tool for modifying the characteristics of PVDF-PZT composites.