FeCl3 doped polyvinylidene fluoride

Tawansi, A.; Abdelkader, H.I.; Balachandran, W.; Abdelrazek, E.M.

doi:10.1007/bf00355961

Cited by 11 publications

(16 citation statements)

References 20 publications

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“…Other absorption bands are noted at 29,000, 29,000, and 28,500 cm Ϫ1 for the respective FL, indicating deeper induced energy bands at 3.6, 3.6, and 3.5 eV below the conduction band. It is noteworthy that the main features of the present spectra are similar to those of Cu 2ϩ doped glasses, where the observed absorption bands within the range of 12,500 -14,500 cm Ϫ1 were assigned to the d-d band of Cu 2ϩ due to the transition between 2 E and 2 T 2 levels, which originate from the splitting of the 2 D ground state of the Cu 2ϩ free ion (d 9 ) in an octahedral field. 23 The absorption band at 28,500 -29,000 cm Ϫ1 can be attributed to the first allowed electron transfer band.…”

Section: Ir Analysismentioning

confidence: 54%

“…This is in good agreement with the results obtained for the previous case of FeCl 3 filling. 9 Comparing Figure 14 with Figure 15, one may find two differently CuCl 2 -filled PVDF films having the same value of ⌽ but of different power reflection values. Pairs of the present films can be used as similar microwave modulators of different attenuation factors.…”

Section: Microwave Responsementioning

confidence: 97%

“…7 It is used in nonlinear optics 8 and microwave transducers. 9 PVDF is a water-resistive material; therefore, it is suitable for outdoor and indoor paintings. 10 Moreover, it has important medical applications 11 because it is nonrejectable in human tissues.…”

Section: Introductionmentioning

confidence: 99%

“…9 The apparatus was of type KDR-10SA crystal mount (ANDO Electric Co., Japan). Experiments were done in 10 GHz band with the waveguides WRJ-10 and flanges BRJ both according to JIS standards.…”

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confidence: 99%

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Effect of valence electron spin polarization on the physical properties of CuCl2-filled poly(vinylidene fluoride) as a microwave modulator

Tawansi

Ayad

Abdelrazek

1999

J. Appl. Polym. Sci.

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Infrared and optical spectra, differential thermal analysis, dc electrical resistivity, magnetic susceptibility, electron spin resonance, and microwave response of CuCl 2 -filled poly(vinylidene fluoride) (PVDF) films, over the filler mass fraction range 0.05 Յ W Յ 0.4, were measured. The infrared spectra evidenced the presence of ␤-phase, for all of the filler levels with main deformations of 20% (for W ϭ 0.25) and 30% (for other filler levels) head-to-head and tail-to-tail units, which were considered as polaron and bipolaron defects. Optical activity was mainly influenced by PVDF structure. Differential thermal analysis revealed dipole relaxation and premelting endothermic peaks. A quasi-one-dimensional interpolaron hopping was thought to proceed in the direct current electric conduction, with a hopping distance less than the distance between two successive head-to-head sites. A temperature-independent Pauli paramagnetic behavior was observed, confirming the presence of induced energy bands due to CuCl 2 filling. Most of the observed electron spin resonance signals were antisymmetric, with superimposed repels due to the hyperfine interactions characterizing PVDF. The obtained linear dependence of the isotropic hyperfine coupling constant (⌬A`), for Cu(II), on average g-factor, implied that ⌬A`is a measure of the valence electron spin polarization. An octahedral or distorted octahedral configuration was suggested for Cu(II). The present system is a good microwave modulator.

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Section: Ir Analysismentioning

confidence: 54%

Section: Microwave Responsementioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

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Effect of valence electron spin polarization on the physical properties of CuCl2-filled poly(vinylidene fluoride) as a microwave modulator

Tawansi

Ayad

Abdelrazek

1999

J. Appl. Polym. Sci.

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“…When crystallization temperature is higher than 435 K the growth rate of γ crystals becomes higher than that of the α-phase as in the present work. Recent investigations of our research group revealed that metal halide fillers modify significantly the structure and physical properties of PVDF films [11,12]. The aim of the present work is to investigate the effect of LaNi 3 Co 2 composites on the structural, physical properties of PVDF films and study the magnetoresistance phenomena.…”

Section: Introductionmentioning

confidence: 98%

Spectroscopic and thermal investigations of poly(vinylidene fluoride) films composites with LaNi₃Co₂

Elashmawi¹,

Elsheshtawi

Abdelkader

et al. 2007

Cryst. Res. Technol.

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Poly(vinylidene fluoride) (PVDF) and LaNi 3 Co 2 were composites in various combinations by using melting technique. Morphological and physical properties of both the surface and interface of poly(vinylidene fluoride)/ LaNi 3 Co 2 composite films have been investigated. FTIR and XRD diffraction analysis evidenced the increase of α, β and γ-PVDF crystalline phases. The bands at 888 and 1414 cm -1 were assigned to γ-phase of PVDF. Maximum value of the relative amount of β-phase was observed at 35 and 60 % FL. This result was confirmed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. Maximum value of degree of crystallinity was observed at 15% Filling level (FL). Morphology of SEM consists of two different size rings and spherulites. DSC was used to identify the melting temperature, the order of reaction and the activation energy of melting. A sharp endothermic peak at T m ≈ 444 K due to melting and T 2 ≈ 360 K due to α-relaxation/transition. Maximum values of magnetoresistance (MR) observed from range (243 to 238K) are due to reorientation of dipoles in a process associated with the glass transition temperature of PVDF.

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Effect of local structure of MnCl2-filled PVDF films on their optical, electrical, electron spin resonance, and magnetic properties

Tawansi

Oraby

Abdelrazek

et al. 1998

J. Appl. Polym. Sci.

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ABSTRACT:The filling level (W ) dependence of the local structure of MnCl 2 through the PVDF matrix was explored. The presence of a-and b-PVDF crystalline phases were detected by X-ray diffraction, and it was confirmed by the infrared (IR) absorption spectra. A significant head-to-head content was implied by IR spectroscopy. Two filling, level-dependent optical energy gaps were found through the UV-VIS spectral investigation. An intrachain one-dimensional interpolaron hopping mechanism was assumed to proceed in the temperature range of 350-375 K. The calculated values of the charge carrier hopping distance were in the range of 6.5-9.7 nm. The temperature dependence of the direct current (dc) magnetic susceptibility exhibited a Curie-Weiss behavior. Positive values of the paramagnetic Curie temperature ( u p ) for W up to 14.5% indicated the presence of a ferromagnetic interaction, while negative u p obtained for higher W values suggested an antiferromagnetic interaction at lower temperature. The electron spin resonance (ESR) analysis revealed the existance of both isolated and aggregated Mn 2/ ions within the PVDF matrix.

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FeCl3 doped polyvinylidene fluoride

Cited by 11 publications

References 20 publications

Effect of valence electron spin polarization on the physical properties of CuCl2-filled poly(vinylidene fluoride) as a microwave modulator

Effect of valence electron spin polarization on the physical properties of CuCl2-filled poly(vinylidene fluoride) as a microwave modulator

Spectroscopic and thermal investigations of poly(vinylidene fluoride) films composites with LaNi₃Co₂

Effect of local structure of MnCl2-filled PVDF films on their optical, electrical, electron spin resonance, and magnetic properties

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FeCl3 doped polyvinylidene fluoride

Cited by 11 publications

References 20 publications

Effect of valence electron spin polarization on the physical properties of CuCl2-filled poly(vinylidene fluoride) as a microwave modulator

Effect of valence electron spin polarization on the physical properties of CuCl2-filled poly(vinylidene fluoride) as a microwave modulator

Spectroscopic and thermal investigations of poly(vinylidene fluoride) films composites with LaNi3Co2

Effect of local structure of MnCl2-filled PVDF films on their optical, electrical, electron spin resonance, and magnetic properties

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Spectroscopic and thermal investigations of poly(vinylidene fluoride) films composites with LaNi₃Co₂