FESEM-EDX and CV Characteristics of Dopant (Mn, Co, Ni) Magnesium Ferrites

2013 ◽  
Vol 645 ◽  
pp. 150-153
Author(s):  
Siti Soleha Jonit ◽  
Madzlan Aziz ◽  
Rita Sundari
Keyword(s):  
Vinylidene Fluoride ◽  
Sol Gel ◽  
Carbon Electrode ◽  
Magnesium Ferrite ◽  
Cyclic Voltammetric ◽  
X Ray ◽  
Screen Printed Carbon Electrode ◽  
Scan Rate ◽  
Poly Vinylidene Fluoride ◽  
Mn Doped

Doping magnesium ferrites (MgFe2 O4) with Mn, Co and Ni, which were synthesized by sol gel method using citric acid and polyvinyl alcohol (P VA) and calcined at 500oC, showed interesting electrochemical featur es based on their cyclic voltammetric (CV) characteristics using 5 µL ferrite – poly vinylidene fluoride in ethano l deposited on a screen printed carbon electrode (SPCE) in a mixture of 1.0 M KOH and ferricyanide solution recorded with a scan rate of 0.02 Vs -1. The Mn doped magnesium ferrite (x = 0.9) showed the most remarkable CV performance over other doped element (Co and Ni) and un-doped magnesiu m ferrites. The surface morphology of doped ferrites was studied by applying a field emissi on scanning electron microscope (FESEM) in conjunction with an energy dispersive X-ray spect roscopy (EDX) analysis. The results revealed that Mn posed the highest percentage on the surface ( ≈ 21.5 %), followed by Co (≈ 19.5%) and Ni ( ≈ 6.7%) with respect to x = 0.9 of M0.9Mg0.1Fe 2 O4 (M = Co, Mn and Ni) at 500oC calcination. The study showed the possibility of yielding semi conducting ferrites using own fabricated magnesium ferrite and its metal doping.

scholarly journals Preparation and Electrochemical Characterization of Organic–Inorganic Hybrid Poly(Vinylidene Fluoride)-SiO2 Cation-Exchange Membranes by the Sol-Gel Method Using 3-Mercapto-Propyl-Triethoxyl-Silane

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3265 ◽  
Author(s):  
Li ◽  
Li ◽  
Li ◽  
Guan ◽  
Zheng ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Oxidative Stability ◽  
Water Uptake ◽  
Polyvinylidene Fluoride ◽  
Vinylidene Fluoride ◽  
Sol Gel ◽  
Synthesis Method ◽  
Co2 Production ◽  
Inorganic Hybrid ◽  
Poly Vinylidene Fluoride

A new synthesis method for organic–inorganic hybrid Poly(vinylidene fluoride)-SiO2 cation-change membranes (CEMs) is proposed. This method involves mixing tetraethyl orthosilicate (TEOS) and 3-mercapto-propyl-triethoxy-silane (MPTES) into a polyvinylidene fluoride (PVDF) sol-gel solution. The resulting slurry was used to prepare films, which were immersed in 0.01 M HCl, which caused hydrolysis and polycondensation between the MPTES and TEOS. The resulting Si-O-Si polymers chains intertwined and/or penetrated the PVDF skeleton, significantly improving the mechanical strength of the resulting hybrid PVDF-SiO2 CEMs. The -SH functional groups of MPTES oxidized to-SO3H, which contributed to the excellent permeability of these CEMs. The surface morphology, hybrid structure, oxidative stability, and physicochemical properties (IEC, water uptake, membrane resistance, membrane potential, transport number, and selective permittivity) of the CEMs obtained in this work were characterized using scanning electron microscope and Fourier transform infrared spectroscopy, as well as electrochemical testing. Tests to analyze the oxidative stability, water uptake, membrane potential, and selective permeability were also performed. Our organic–inorganic hybrid PVDF-SiO2 CEMs demonstrated higher oxidative stability and lower resistance than commercial Ionsep-HC-C membranes with a hydrocarbon structure. Thus, the synthesis method described in this work is very promising for the production of very efficient CEMs. In addition, the physical and electrochemical properties of the PVDF-SiO2 CEMs are comparable to the Ionsep-HC-C membranes. The electrolysis of the concentrated CoCl2 solution performed using PVDF-SiO2-6 and Ionsep-HC-C CEMs showed that at the same current density, Co2+ production, and current efficiency of the PVDF-SiO2-6 CEM membrane were slightly higher than those obtained using the Ionsep-HC-C membrane. Therefore, our novel membrane might be suitable for the recovery of cobalt from concentrated CoCl2 solutions.

Temperature-dependent small-angle x-ray scattering from poly(vinylidene fluoride)

1980 ◽  
Vol 51 (10) ◽  
pp. 5508 ◽  
Author(s):  
J. M. Schultz ◽  
J. S. Lin ◽  
R. W. Hendricks ◽  
R. R. Lagasse ◽  
R. G. Kepler
Keyword(s):  
Small Angle ◽  
Vinylidene Fluoride ◽  
Temperature Dependent ◽  
X Ray ◽  
X Ray Scattering ◽  
Poly Vinylidene Fluoride ◽  
Ray Scattering

Kinetic of poly(vinylidene fluoride) defluorination under X-ray irradiation

2010 ◽  
Vol 4 (1) ◽  
pp. 122-127 ◽  
Author(s):  
A. M. Kuvshinov ◽  
S. S. Chebotaryov ◽  
L. A. Pesin ◽  
I. V. Gribov ◽  
N. A. Moskvina ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
X Ray ◽  
Poly Vinylidene Fluoride

Simulations of High-Strain Electrostrictive Chlorinated Terpolymers

2003 ◽  
Vol 785 ◽  
Author(s):  
George J. Kavarnos ◽  
Thomas Ramotowski
Keyword(s):  
Vinylidene Fluoride ◽  
High Strain ◽  
Polymer Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lamellar Structures ◽  
Annealing Conditions ◽  
Poly Vinylidene Fluoride ◽  
Electromechanical Responses ◽  
Kinetics Of

ABSTRACTChlorinated poly(vinylidene fluoride/trifluoroethylene) terpolymers are remarkable examples of high strain electrostrictive materials. These polymers are synthesized by copolymerizing vinylidene fluoride and trifluoroethylene with small levels of a third chlorinated monomer. The electromechanical responses of these materials are believed to originate from the chlorine atom, which, by its presence in the polymer chains and by virtue of its large van der Waals radius, destroys the long-range crystalline polar macro-domains and transforms the polymer from a normal to a high-strain relaxor ferroelectric. To exploit the strain properties of the terpolymer, it is desirable to understand the structural implications resulting from the presence of the chlorinated monomer. To this end, computations have been performed on model superlattices of terpolymers using quantum-mechanical based force fields. The focus has been on determining the energetics and kinetics of crystallization of the various polymorphs that have been identified by x-ray diffraction and fourier transform infrared spectroscopy. The chlorinated monomer is shown to act as a defect that can be incorporated into the lamellar structures of annealed terpolymer without a high cost in energy. The degree of incorporation of the chlorinated monomer into the crystal lattice is controlled by annealing conditions and ultimately determines the ferroelectric behavior of the terpolymers.

SURFACE PHOTODEGRADATION OF POLY(VINYLIDENE FLUORIDE) BY INNER-SHELL EXCITATION

2006 ◽  
Vol 13 (02n03) ◽  
pp. 259-263 ◽  
Author(s):  
KOJI KAMIYA OKUDAIRA ◽  
EIICHI KOBAYASHI ◽  
KAZUHIKO MASE ◽  
SATOSHI KERA ◽  
NOBUO UENO
Keyword(s):  
Vinylidene Fluoride ◽  
Early Stage ◽  
Pvdf Film ◽  
Double Bonds ◽  
X Ray ◽  
Hybrid State ◽  
Nexafs Spectrum ◽  
Backbone Chain ◽  
Bond Scission ◽  
Poly Vinylidene Fluoride

Poly(vinylidene fluoride) (PVDF, –( CH 2– CF 2)n–) shows the effective H + desorption induced by the irradiation of photon corresponding to the transition from carbon ( C ) 1s to σ( C – H )*. In order to clarify the effect of the C – H bond scission by the irradiation, near-edge X-ray absorption fine structure (NEXAFS) spectra and the kinetic energy (Ek) distribution of desorbed ion were observed. By the irradiation of photon near C 1s region, a new peak appears in the C 1s NEXAFS spectra at photon energy of 285 eV, which is about 3 eV lower than that of the lowest peak in the NEXAFS spectrum of the pristine PVDF film. The appearance of the lowest NEXAFS peak of irradiated PVDF film is assigned to the transition to π*. It indicates that the irradiation of photons near C 1s region introduces carbon–carbon double bonds into the backbone chain of PVDF. At early stage of X-ray exposure the yield of desorbed ion with low Ek (~ 2 eV) decreases rapidly. The ion with low Ek is assigned to H + desorbed from the sp3-hybrid state, which is characteristics of the pristine PVDF. It indicates that formation of double bonds in PVDF backbone chain makes the number of sp3-hybrid state decrease. This variation occurs by irradiation of photons corresponding to the transition from C 1s to σ( C – H )* more rapidly than that to the transition to σ( C – F )*.

Structures and Physical Properties of Multi-Walled Carbon Nanotube-Filled PVDF Thermoplastic Composites

2007 ◽  
Vol 124-126 ◽  
pp. 1117-1120 ◽  
Author(s):  
Dong Wook Chae ◽  
Young Wan Nam ◽  
Seung Sangh Wang ◽  
S.M. Hong
Keyword(s):  
Carbon Nanotube ◽  
Vinylidene Fluoride ◽  
Thermoplastic Composites ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Loading Level ◽  
Multi Walled Carbon Nanotube ◽  
Poly Vinylidene Fluoride ◽  
Internal Mixer

Poly(vinylidene fluoride) (PVDF) / multi-walled carbon nanotube (MWNT) thermoplastic composites was melt compounded in an internal mixer. The percolation level for this system in electrical conductivity clearly occured between 2 and 2.5 wt%. PVDF/MWNT thermoplastic composites exhibited an increased crystallization temperature with the loading level, at 10 wt% loading by ca. 6. In addition, they presented a shoulder posterior to the main melting peak and an increased endpoint of the peak. In the Wide Angle X-ray Diffraction (WAXD) patterns, the incorporation of MWNT produced a larger shoulder at 2θ =20.7° with increasing the loading level, corresponding to the β-form crystal of PVDF.

The Synthesis and Electrochemical Performance of LiV3O8 Cathode with Lanthanum-Doped

2012 ◽  
Vol 560-561 ◽  
pp. 860-863
Author(s):  
Fang Hu ◽  
Mo Ran Sun ◽  
Yu Sheng Wu ◽  
Chun Hua Zhang
Keyword(s):  
Sol Gel ◽  
Discharge Voltage ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Galvanostatic Charge ◽  
Cyclic Voltammetric ◽  
Voltage Range ◽  
X Ray ◽  
Voltage Plateau ◽  
First Discharge Capacity

Li1-xLaxV3O8 cathode materials has been synthesized by pechini sol-gel method. The electrochemical performances of Li1-xLaxV3O8(x=0-0.05) have been studied by X-ray diffraction (XRD), galvanostatic charge-discharge, and cyclic voltammetric (CV). The results showed that the optimal content of the La3+ doping in LiV3O8 was x=0.01, and the first discharge capacity of Li0.99La0.01V3O8 sample in the voltage range of 2.0-4.0V was 230mAhg-1, which was much higher than that of LiV3O8 (200mAhg-1). The Li0.99La0.01V3O8 cathode also showed higher discharge voltage plateau than LiV3O8 cathode from the CV curves.

Radiative defluorination of poly (vinylidene fluoride) under soft X-ray radiation

2006 ◽  
Vol 75 (11) ◽  
pp. 2024-2028 ◽  
Author(s):  
S.S. Chebotaryov ◽  
E.M. Baitinger ◽  
A.A. Volegov ◽  
I.G. Margamov ◽  
I.V. Gribov ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
X Ray ◽  
Poly Vinylidene Fluoride

scholarly journals Influence of molecular weight on dielectric properties and piezoelectric constant of poly(vinylidene fluoride) membranes obtained by electrospinning

Polimery ◽  
2021 ◽  
Vol 66 (10) ◽  
pp. 532
Author(s):  
Aminatul Sobirah Zahari ◽  
Muhammad Hafiz Mazwir ◽  
Izan Izwan Misnon
Keyword(s):  
Molecular Weight ◽  
Dielectric Properties ◽  
Vinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Piezoelectric Constant ◽  
Phase Content ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

A significant influence of the molecular weight on the dielectric properties and piezoelectric constant of poly(vinylidene fluoride) (PVDF) membranes obtained by electrospinning was demonstrated. Electrochemical impedance spectroscopy and d33 meter were used to evaluate dielectric properties and piezoelectric constant respectively. The presence of the β-phase was determined by Fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD). The membranes with the lowest molecular weight (180,000 g/mol) possessed the best dielectric properties. They also had the highest piezoelectric constant (21 pC/N) and dielectric constant (2.9 at 50 Hz) as well as the highest β-phase content (80.25%).

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