Crystallization and Matrix Effects on the Electronic Properties of Polymers Doped with CT Salts of TCNQ

1990 ◽  
Vol 214 ◽  
Author(s):  
Yang-Cheng Fann ◽  
Susan A. Jansen ◽  
Marygail Hutchins
Keyword(s):  
Magnetic Properties ◽  
Molecular Electronics ◽  
Polymer Matrix ◽  
Polymer Films ◽  
Matrix Effects ◽  
Evaporation Process ◽  
Conductivity Measurements ◽  
The Matrix ◽  
Doped Polymer ◽  
Ct Complexes

ABSTRACTMolecularly doped polymer films have shown potential for applications in electrophotography and molecular electronics. The electrooptical and magnetic properties as well as conductivities are enhanced significantly by doping chargetransfer(CT) complexes or dye into a polymeric matrix, by comparison with nondoped polymer films.Polycarbonate films doped with CT complexes based on 7,7′,8,8′- tetracyanoquinodimethane( TCNQ) were studied from 100K to 450K. Crystallization and formation of ‘nearly’ spaced aggregates within the polymer matrix were observed. These phenomena were affected by several factors such as the film thickness, evaporation process, temperature and concentration within the polymer matrix. Discontinuities in magnetic properties at 200K, possibly due to solvent encapsulation in the matrix, and at about 385K due to glass transition of the polymer were observed.Characterization, conductivity measurements in comparison with pristine complexes, and photoirradiation studies on these doped films are presented.

Theoretical and experimental investigation of the particle size distribution and magnetic properties of the PP + FE3O4nanocomposites

2019 ◽  
Vol 33 (1) ◽  
pp. 125-137
Author(s):  
Mahammadali A Ramazanov ◽  
Abel M Maharramov ◽  
Rasim A Ali-zada ◽  
Habiba A Shirinova ◽  
Flora V Hajiyeva
Keyword(s):  
Magnetic Properties ◽  
Size Distribution ◽  
Polymer Matrix ◽  
Theoretical Calculations ◽  
Mixing Time ◽  
Magnetic Hysteresis ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Matrix ◽  
Scanning Electron

A detailed study of the dispersion of magnetite (Fe3O4) nanoparticles in the polypropylene (PP) matrix, the degree of coagulation, and the dependence of magnetic properties of PP + Fe3O4nanocomposites on the size of nanoparticles is reported. The size distribution of nanoparticles in polymer matrix and morphology of the nanocomposites were studied by the means of scanning electron microscope (JEOL JSM-7600 F) and atomic force microscopy (NT-MDT). It was found that when the Fe3O4nanoparticles are introduced into the PP matrix, their coagulation takes place. The increase in the size of the Fe3O4nanoparticles depends on their volume content in the polymer matrix, the viscosity of polymer, mixing time, and so on. The magnetic properties of PP + Fe3O4nanocomposites were experimentally and theoretically studied. It was found that the magnetic hysteresis parameters of the nanocomposites directly depend on the size and concentration of the Fe3O4nanoparticles in the matrix. Theoretical calculations were compared with experimental results obtained from M( H) measurements. Discrepancy between theoretical and experimental magnetic values have been explained.

scholarly journals Investigating the Effect of Zn Ferrite Nanoparticles on the Thermomechanical, Dielectric and Magnetic Properties of Polymer Nanocomposites

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3015 ◽  
Author(s):  
Aikaterini Sanida ◽  
Sotirios G. Stavropoulos ◽  
Thanassis Speliotis ◽  
Georgios C. Psarras
Keyword(s):  
Magnetic Properties ◽  
Polymer Matrix ◽  
Quantum Interference ◽  
Zinc Ferrite ◽  
Interfacial Polarization ◽  
Ferrite Nanoparticles ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Zn Ferrite ◽  
The Matrix

In this study nanocomposites consisting of an epoxy resin and ceramic zinc ferrite nanoparticles have been successfully developed and investigated morphologically and structurally by means of scanning electron microscopy (SEM) images and X-ray diffraction (XRD) spectra. The thermal properties of the nanocomposites were studied via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The thermomechanical characterization of the fabricated nanocomposites was studied via dynamic mechanical analysis (DMA) and the magneto-dielectric response was assessed by means of a broadband dielectric spectroscopy (BDS) and by employing a superconducting quantum interference device (SQUID) magnetometer. Data analysis demonstrates that the incorporation of nanoinclusions into the matrix improves both the thermomechanical and the dielectric properties of the systems, as indicated by the increase of the storage modulus, the real part of dielectric permittivity and conductivity values with filler content, while at the same time induces magnetic properties into the matrix. Zinc ferrite nanoparticles and their respective nanocomposites exhibit superparamagnetic behavior at room temperature. Three relaxations were recorded in the dielectric spectra of all systems; originating from the filler and the polymer matrix, namely interfacial polarization, glass to rubber transition of the polymer matrix and the reorientation of small polar side groups of the polymer chain.

Complexes of copper(II) and nickel(II) with a Schiff base bonded to a polymeric support

1983 ◽  
Vol 48 (7) ◽  
pp. 2021-2027 ◽  
Author(s):  
Eliška Kálalová ◽  
Olga Populová ◽  
Štěpánka Štokrová ◽  
Pavel Stopka
Keyword(s):  
Magnetic Properties ◽  
Schiff Base ◽  
Coordination Sphere ◽  
Polymer Matrix ◽  
Glycidyl Methacrylate ◽  
Epr Spectra ◽  
Polymeric Support ◽  
Tetrahedral Configuration ◽  
Paramagnetic Complexes

Copper(II) and nickel(II) ions were bonded in complexes of salicylideneimine type on a glycidyl methacrylate-ethylenedimethacrylate copolymer. The geometry of the complexes on the polymer was studied by measuring their magnetic properties, EPR spectra, and ultraviolet-visible spectra.Only paramagnetic complexes possessing a pseudo-tetrahedral configuration were found. The effect of the polymer matrix and of the immobility of the bonded Schiff base on the distortion of the coordination sphere of the central ion is discussed.

scholarly journals A mechanism for fire retardancy realized by a combination of biofillers and ammonium polyphosphate in various polymer systems

Cellulose ◽  
2021 ◽  
Author(s):  
Koki Matsumoto ◽  
Tatsuya Tanaka ◽  
Masahiro Sasada ◽  
Noriyuki Sano ◽  
Kenta Masuyama
Keyword(s):  
Polymer Matrix ◽  
Synergetic Effect ◽  
Polymer System ◽  
Ammonium Polyphosphate ◽  
Fire Retardancy ◽  
Polymer Systems ◽  
Thermal Decomposition Behavior ◽  
Burning Behavior ◽  
The Matrix ◽  
Decomposition Behavior

AbstractThis study focused on realizing fire retardancy for polymer composites by using a cellulosic biofiller and ammonium polyphosphate (APP). The motivation of this study was based on revealing the mechanism of the synergetic effect of a cellulosic biofiller and APP and determining the parameters required for achieving a V-0 rating in UL94 standard regardless of the kind of polymer system used. As for the polymer matrix, polypropylene and polylactic acid were used. The flammability, burning behavior and thermal decomposition behavior of the composites were investigated through a burning test according to the UL-94 standard, cone calorimetric test and thermogravimetric analysis. As a result, the incorporation of a high amount of cellulose enabled a V-0 rating to be achieved with only a small amount of APP despite the variation of the optimum cellulose loading between the matrix polymers. Through analysis, the results indicated that APP decreased the dehydration temperature of cellulose. Furthermore, APP promoted the generation of enough water as a nonflammable gas and formed enough char until the degradation of the polymer matrix was complete. The conditions required to achieve the V-0 rating were suggested against composites incorporating APP and biofillers. Furthermore, the suggested conditions were validated by using polyoxymethylene as a highly flammable polymer.

scholarly journals Comparison of the Dielectric Properties of Ecoflex® with L,D-Poly(Lactic Acid) or Polycaprolactone in the Presence of SWCN or 5CB

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1719
Author(s):  
Patryk Fryń ◽  
Sebastian Lalik ◽  
Natalia Górska ◽  
Agnieszka Iwan ◽  
Monika Marzec
Keyword(s):  
Oleic Acid ◽  
Dielectric Properties ◽  
Polymer Matrix ◽  
Liquid Crystalline ◽  
Weight Ratio ◽  
Poly Lactic Acid ◽  
Relaxation Processes ◽  
The Matrix ◽  
Walled Carbon Nanotubes ◽  
Hybrid Layers

The main goal of this paper was to study the dielectric properties of hybrid binary and ternary composites based on biodegradable polymer Ecoflex®, single walled carbon nanotubes (SWCN), and liquid crystalline 4′-pentyl-4-biphenylcarbonitrile (5CB) compound. The obtained results were compared with other created analogically to Ecoflex®, hybrid layers based on biodegradable polymers such as L,D-polylactide (L,D-PLA) and polycaprolactone (PCL). Frequency domain dielectric spectroscopy (FDDS) results were analyzed taking into consideration the amount of SWCN, frequency, and temperature. For pure Ecoflex®, two relaxation processes (α and β) were identified. It was shown that the SWCN admixture (in the weight ratio 10:0.01) did not change the properties of the Ecoflex® layer, while in the case of PCL and L,D-PLA, the layers became conductive. The dielectric constant increased with an increase in the content of SWCN in the Ecoflex® matrix and the conductive behavior was not visible, even for the greatest concentration (10:0.06 weight ratio). In the case of the Ecoflex® polymer matrix, the conduction relaxation process at a frequency ca. several kilohertz appeared and became stronger with an increase in the SWCN admixture in the matrix. Addition of oleic acid to the polymer matrix had a smaller effect on the increase in the dielectric response than the addition of liquid crystal 5CB. Fourier transform infrared (FTIR) results revealed that the molecular structure and chemical character of the Ecoflex® and PCL matrixes remained unchanged upon the addition of SWCN or 5CB in a weight ratio of 10:0.01 and 10:1, respectively, while molecular interactions appeared between L,D-PLA and 5CB. Moreover, adding oleic acid to pure Ecoflex® as well as the binary and ternary hybrid layers with SWCN and/or 5CB in a weight ratio of Ecoflex®:oleic acid equal to 10:0.3 did not have an influence on the chemical bonding of these materials.

Doped polymer films with high nonlinear refractive indices

1996 ◽  
Vol 32 (2) ◽  
pp. 129 ◽  
Author(s):  
Z.X. Zhang ◽  
W. Qiu ◽  
E.Y.B. Pun ◽  
P.S. Chung ◽  
Y.Q. Shen
Keyword(s):  
Polymer Films ◽  
Refractive Indices ◽  
Doped Polymer

The matrix effects on kinetic rate constants of antibody–antigen interactions reflect solvent viscosity

1998 ◽  
Vol 217 (1-2) ◽  
pp. 51-60 ◽  
Author(s):  
Claire L. Morgan ◽  
David J. Newman ◽  
Jacky M. Burrin ◽  
Christopher P. Price
Keyword(s):  
Rate Constants ◽  
Matrix Effects ◽  
Kinetic Rate ◽  
Solvent Viscosity ◽  
Kinetic Rate Constants ◽  
The Matrix

scholarly journals The Effect of Aging on Precipitates, Mechanical and Magnetic Properties of Fe-21Cr-15Ni-6Mn-Nb Low Magnetic Stainless Steel

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 819
Author(s):  
Changsheng Li ◽  
Kun Li ◽  
Jingbo Dong ◽  
Jinyi Ren ◽  
Yanlei Song
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Stainless Steel ◽  
Magnetic Properties ◽  
Solution Heat Treatment ◽  
Aging Treatment ◽  
Relative Magnetic Permeability ◽  
Coarsening Behavior ◽  
The Matrix ◽  
Coherent Orientation

The effect of aging on the precipitates, mechanical and magnetic properties of Fe-21Cr-15Ni-6Mn-Nb low magnetic stainless steel were investigated. The steel was aged at 550–750 °C for 2 h after solution heat treatment at 1100 °C for 1 h. During the aging treatment, the (Nb, V)(C, N) particles gradually precipitated in the grain, which were coherent or semi-coherent with the matrix. When the aging temperature was beyond 650 °C, the coarsening rate of (Nb, V)(C, N) particles increase rapidly and the coherent orientation between (Nb, V)(C, N) particles and the matrix was lost gradually. Meanwhile, coarse M23C6 was distributed at the grain boundary with chain shape, which was non-coherent with the matrix. The coarsening behavior of (Nb, V)(C, N) precipitates in the grain was analyzed, and the size of the particles precipitated after aging treatment at 650°C for different time was calculated and studied. After aging treatment at 650 °C for 2 h, the yield strength and tensile strength of the stainless steel was 705.6 MPa and 1002.3 MPa, the elongation and the relative magnetic permeability was 37.8% and 1.0035, respectively.

Atmospheric effects on corona poling of nonlinear optical doped polymer films

1990 ◽  
Author(s):  
Shelly J. Bethke ◽  
Stephen G. Grubb ◽  
Hilary S. Lackritz ◽  
John M. Torkelson
Keyword(s):  
Polymer Films ◽  
Nonlinear Optical ◽  
Atmospheric Effects ◽  
Corona Poling ◽  
Doped Polymer
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