Thermally stimulated depolarization currents in poly(acrylamide) films

Abstract

The charge storage mechanism in poly(aery1amide) films was studied by means of the technique of thermally stimulated depolarization currents (TSDC). The TSDC were measured as a function of field strength, temperature and time of polarization in dependence on the heating rate. One peak was observed on the TSDC spectra a t low polarizing temperatures, while two peaks occurred for higher polarizing temperatures. The first peak was attributed to dipole orientation and the second one to space charge polarization. Thermisch sliniulierte Depolarisationsslrdme in Poly(acnj1amid)-FilnienDer Mechanismus der Ladungsspeicherung in Poly(acry1amid)-Filmen wurdc mit der Methode der thermisch stimulierten Depolarisationsstrome (TSDC) untersucht. Die TSDC wurden in Abhiingigkeit von dcr Feldstiirke, der Tempe. ratur und der Dauer dcr Polarisation bei verschiedenen Aufheizgeschwindigkeitcn gemessen. Bei niedrigen Polarisationstemperaturen wurdc in den TSDC-Spcktren nur ein Peak gefundcn, bei holieren Polarisationstemperaturen tratcn zwei Peaks auf. Der erste Peak wurde der Dipolorientierung, der zweite der Raumladungspolarisation zugeordnet.

Studies on some rare earth metal complexes: Ten- and six-coordinated complexes of an unsymmetrical aminoacid derivative

“…It is well-known that restricted rotation about the carbon-to-nitrogen bond in a number of amides leads to the existence of geometrical isomers (Lewin et al 1975). The present case is similar those of salicylaldehyde (N-benzoyl) glycyl hydrazone (Rao and Singh 1991) and furfural (N-benzoyl)glycyl hydrazone (Lonibala 1992) where two isomers were shown in each case. These isomers are usually non-separable due to the relatively low barrier to rotation (Stewart and Sidall 1970).…”

Tunable optical and dielectric properties of polymeric composite materials based on magneso-silicate

“…It can be seen that the initial conductivity increases up to 87 • C, followed by a moderate increase up to 300 • C, and then a final rapid decrease from 300 to 441 • C. This behaviour was assigned to the conversion of polymer to metallic MgSi, elimination of organic components from the polymer phase to form the composites of magnesium silicate. Narasimha Rao and Subba [57] reported thermally stimulated discharge currents in the composite polymer as a function of the polarizing field strength and concluded that the Poole-Frenkel model describes the dominant mechanism. Blythe [58] stated that polyamides show pronounced ionic conduction effects at elevated temperatures, evidently as a result of the dissociation of amide groups to give protons [59].…”