Air-gap thermally stimulated discharge currents in PVDF-PMMA double-layered samples

• Published in: Journal of thermal analysis and calorimetry Vol. 147; no. 4; pp. 2957 - 2968
• Main Authors: Saxena, Pooja, Shukla, Prashant, Gaur, M. S.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.02.2022; Springer; Springer Nature B.V
• Subjects: Air gaps; Analytical Chemistry; Chemistry; Chemistry and Materials Science; Depolarization; Dielectric films; Discharge; Electric fields; Fluorides; High temperature; Inorganic Chemistry; Measurement Science and Instrumentation; Methyl methacrylate; Physical Chemistry; Polarization; Polymer films; Polymer Sciences; Polymethyl methacrylate; Polyvinylidene fluoride; Polyvinylidene fluorides; Thin films; Vinylidene fluoride; Space charge; Bulk; Air gap TSDC; Electret
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-021-10680-y

In this paper, we have reported the interpretation of air gap TSDC of surface charges in polyvinylidene fluoride (PVDF)-poly (methyl methacrylate) PMMA double-layered polymer thin films. The influence of the layered structure semicrystalline poly (vinylidene fluoride) (PVDF) and amorphous poly (methyl methacrylate) (PMMA) on their electret properties was investigated in detail using the air gap thermally stimulated discharge current technique. Hetero-charge persists at high temperatures due to the electric field produced by the homo-charge owing to bulk polarization. Hence, the depolarization current observed in the present study was found to be of opposite polarity as that of polarization current and also this layered structure was found to be a source of charge trapping which was identified by the behavior of TSDC peak. Each TSDC characteristics is characterized by three peaks, namely α, β, and γ. Each TSDC characteristic was begun with a high amount of initial charge and will increase the drift because it increases the field that drives the charges to adhering back electrode. This also confirms the peak is caused by the motion of excess charges.