Ceria/ PVDF/PVDF-HFP Nanocomposite: Designing, Characterization, Optical, Piezo- and Pyroelectric Properties for Energy Storage Systems
A. Habib, T. Fahmy, A. Almalki, M. M. Metwally
Abstract
Abstract Poly vinylidene fluoride (PVDF) is blended with poly (vinylidene fluoride-co-hexafluoro propylene) (PVDF-HFP) via solution-casting technique. Herein, various concentrations of ex-situ synthetic ceria nanoparticles (CeO 2 NPs) were incorporated within a (50/50 wt% PVDF/PVDF-HFP) polymeric blend (PB). The prepared ceria nanocomposites were characterized by X- ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transformed infrared (ATR-FTIR) and UV/Vis analysis. XRD and FTIR analysis confirmed that the crystalline electroactive β-phase in the PVDF and PVDF-HFP is enhanced after blending and doping with CeO 2 NPs. UV/Vis analysis showed that both direct and indirect band gaps for nanocomposites films are reduced to be about 3.37 and 3.2 eV, respectively. Thermally stimulated depolarization current (TSDC) measurement of the different relaxation phases with polarization in the corona discharge field for different prepared samples had been obtained. TSDC results of the main β-relaxation peak show an enhancement of the relaxation time (τ) and decrease in activation energy (E a ), which is related to higher regularity of the system structure. The piezo- and pyroelectric activity of the various prepared samples were investigated. Pyroelectric coefficient enhanced to be about ≈ 68.5 µC/m 2 K for 20wt.% CeO 2 /PB. The high piezoelectric coefficient d 33 obtained for 20wt.% CeO 2 /PB was about 37.2 pC/N. This innovative flexible piezoelectric structure emerges as a strongly favorable candidate that can be applied as intelligent stress-responsive materials utilized in various energies harvesting piezoelectric technologies.