Effect of AgNO₃–MnCl₂ mixed fillers on the physical properties of polystyrene films

Abstract

This study deals with the effects of various filling levels of a mixture of two transition compounds [(X)AgNO 3 (10 Ϫ X)MnCl 2 ] on the structural, electrical, and magnetic properties of atactic polystyrene (PS) films. X-ray diffraction (XRD) scans showed two main peaks for unfilled PS films. Crystalline peaks were unexpectedly detected with the filling and could be correlated to the formation of clusters. The IR transmission spectra revealed characteristic PS peaks. Certain IR peaks could be taken as evidence for the formation of polaron and bipolaron bound states in the polymeric matrix. The direct-current (DC) electrical conduction measurements suggested that the conduction mechanism could be attributed to phonon-assisted charge carrier hopping according to the interpolaron hopping model. The DC magnetic susceptibility results at 90 -235 K obeyed the Curie-Weiss law. The negative values of the paramagnetic Curie temperature ( p ) indicated the possibility of an antiferromagnetic exchange interaction, whereas the positive values of p suggested a ferromagnetic exchange interaction at low temperatures. An electron spin resonance (ESR) spectrum at X ϭ 0% revealed a broad Lorentzian signal. This suggested the presence of aggregated Mn 2ϩ and was confirmation of cluster formation found in XRD studies. On the other hand, ESR spectra at higher values of X depicted hyperfine structures characterized by the six unresolved lines of the manganese nucleus, indicating the existence of isolated Mn 2ϩ .

Structural, electrical and magnetic properties of polystyrene films filled with AgNO3–FeCl3 mixed fillers

“…The above assigned crystalline peaks can be attributed to the formation of clusters. This explanation agrees quite well with the ESR interpretation of the formation of aggregated Fe 3+ and the absence of isolated Fe 3+ [10,13,[22][23][24][25][26][27]. Generally, it is clear that at X ¼ 1%, the aggregation (clusters) is basically due to FeCl 3 filler, while at X ¼ 9%, the aggregation (clusters) is basically due to AgNO 3 filler.…”

“…It is worthy to note that the magnetic centers responsible for the observed broad and narrow ESR signals can basically be assigned to localized and delocalized polarons, respectively, formed during filling [25,46]. Moreover, the formation of polarons is also confirmed from the present DC electrical conduction results where the conduction mechanism was interpreted on the basis of the phonon-assisted charge carrier hopping between polaron and/or bipolaron bound states in the polymeric matrix.…”

“…Moreover, the broad signal can be explained by the absence of isolated Fe 3+ and the presence of Fe 3+ -Fe 3+ exchange interaction leading to the existence of aggregated Fe 3+ due to the proximity of iron ions [10,13,[22][23][24][25][26][27]. Consequently, the ESR demonstrations imply the formation of Fe 3+ cluster in the polymeric matrix [10,24,25]. In addition, the unexpected appearance of the crystalline peaks noticed by XRD investigations in the present work also confirms the formation of Fe 3+ cluster.…”

Terthiophene-Containing Copolymers and Homopolymer Blends as High-Performance Dielectric Materials

“…38 The commercial PS homopolymer used in this work is atactic and amorphous. Its XRD pattern agrees well with that reported previously 44,45 and consists entirely of an amorphous halo with broad peaks centered at 2θ = 8.4°and 19.1°.…”

Fabrication of Dense Cerium Pyrophosphate-Polystyrene Composite for Application as Low-Temperature Proton-Conducting Electrolytes

“…Though the intensity of the diffraction pattern of the CGP-PS composite in graph (b) is markedly diminished compared to that of CGP, however, it shows no visible difference in terms of the number of diffraction peaks and their positions. Also, the characteristic broad peak around 20 • for the amorphous polystyrene 25 is missing in the diffraction pattern of the CGP-PS1 composite, which could be due to the fact that the amount of polystyrene formed into the pores of the pre-sintered CGP disk is very low and it could not be detected by the XRD measurement system used in the present study.…”