scholarly journals Structural, Morphological, Electrical and Electrochemical Properties of PVA: CS-Based Proton-Conducting Polymer Blend Electrolytes

Membranes ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 71 ◽  
Author(s):  
Ayub Shahab Marf ◽  
Ranjdar M. Abdullah ◽  
Shujahadeen B. Aziz
Keyword(s):  
Polymer Blend ◽  
Structural Changes ◽  
Electrochemical Impedance ◽  
Low Frequency ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
The Relationship ◽  
Added Salt

Polymer blend electrolytes based on poly(vinyl alcohol):chitosan (PVA:CS) incorporated with various quantities of ammonium iodide were prepared and characterized using a range of electrochemical, structural and microscopic techniques. In the structural analysis, X-ray diffraction (XRD) was used to confirm the buildup of the amorphous phase. To reveal the effect of dopant addition on structural changes, field-emission scanning electron microscope (FESEM) was used. The protrusions of salt aggregates with large quantity were seen at the surface of the formed films at 50 wt.% of the added salt. The nature of the relationship between conductivity and dielectric properties was shown using electrochemical impedance spectroscopy (EIS). The EIS spectra were fitted with electrical equivalent circuits (EECs). It was observed that both dielectric constant and dielectric loss were high in the low-frequency region. For all samples, loss tangent and electric modulus plots were analyzed to become familiar with the relaxation behavior. Linear sweep voltammetry (LSV) and transference number measurement (TNM) were recorded. A relatively high cut-off potential for the polymer electrolyte was obtained at 1.33 V and both values of the transference number for ion (tion) and electronic (telec) showed the ion dominant as charge carrier species. The TNM and LSV measurements indicate the suitability of the samples for energy storage application if their conductivity can be more enhanced.

scholarly journals Structural, Impedance, and EDLC Characteristics of Proton Conducting Chitosan-Based Polymer Blend Electrolytes with High Electrochemical Stability

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3508 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
Rebar T. Abdulwahid ◽  
Muhamad H. Hamsan ◽  
Mohamad A. Brza ◽  
Ranjdar M. Abdullah ◽  
...  
Keyword(s):  
Double Layer ◽  
Polymer Blend ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Electrochemical Stability ◽  
Dc Conductivity ◽  
Transference Numbers ◽  
Cyclic Voltammogram ◽  
Casting Technique

In this report, a facile solution casting technique was used to fabricate polymer blend electrolytes of chitosan (CS):poly (ethylene oxide) (PEO):NH4SCN with high electrochemical stability (2.43V). Fourier transform infrared (FTIR) spectroscopy was used to investigate the polymer electrolyte formation. For the electrochemical property analysis, cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) techniques were carried out. Referring to the FTIR spectra, a complex formation between the added salt and CS:PEO was deduced by considering the decreasing and shifting of FTIR bands intensity in terms of functional groups. The CS:PEO:NH4SCN electrolyte was found to be electrochemically stable as the applied voltage linearly swept up to 2.43V. The cyclic voltammogram has presented a wide potential window without showing any sign of redox peaks on the electrode surface. The proved mechanisms of charge storage in these fabricated systems were found to be double layer charging. The EIS analysis showed the existence of bulk resistance, wherein the semicircle diameter decreased with increasing salt concentration. The calculated maximum DC conductivity value was observed to be 2.11 × 10−4 S/cm for CS:PEO incorporated with 40 wt% of NH4SCN salt. The charged species in CS:PEO:NH4SCN electrolytes were considered to be predominantly ionic in nature. This was verified from transference number analysis (TNM), in which ion and electron transference numbers were found to be tion = 0.954 and tel = 0.045, respectively. The results obtained for both ion transference number and DC conductivity implied the possibility of fabricating electrolytes for electrochemical double layer capacitor (EDLC) device application. The specific capacitance of the fabricated EDLC was obtained from the area under the curve of the CV plot.

scholarly journals A Study of Methylcellulose Based Polymer Electrolyte Impregnated with Potassium Ion Conducting Carrier: Impedance, EEC Modeling, FTIR, Dielectric, and Device Characteristics

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4859
Author(s):  
Muaffaq M. Nofal ◽  
Jihad M. Hadi ◽  
Shujahadeen B. Aziz ◽  
Mohamad A. Brza ◽  
Ahmad S. F. M. Asnawi ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Double Layer ◽  
Electrochemical Impedance ◽  
Low Frequency ◽  
Linear Sweep Voltammetry ◽  
High Specific Capacitance ◽  
Transference Number ◽  
Sweep Rate ◽  
Electrochemical Characteristics ◽  
Ion Conducting

In this research, a biopolymer-based electrolyte system involving methylcellulose (MC) as a host polymeric material and potassium iodide (KI) salt as the ionic source was prepared by solution cast technique. The electrolyte with the highest conductivity was used for device application of electrochemical double-layer capacitor (EDLC) with high specific capacitance. The electrical, structural, and electrochemical characteristics of the electrolyte systems were investigated using various techniques. According to electrochemical impedance spectroscopy (EIS), the bulk resistance (Rb) decreased from 3.3 × 105 to 8 × 102 Ω with the increase of salt concentration from 10 wt % to 40 wt % and the ionic conductivity was found to be 1.93 ×10−5 S/cm. The dielectric analysis further verified the conductivity trends. Low-frequency regions showed high dielectric constant, ε′ and loss, ε″ values. The polymer-salt complexation between (MC) and (KI) was shown through a Fourier transformed infrared spectroscopy (FTIR) studies. The analysis of transference number measurement (TNM) supported ions were predominantly responsible for the transport process in the MC-KI electrolyte. The highest conducting sample was observed to be electrochemically constant as the potential was swept linearly up to 1.8 V using linear sweep voltammetry (LSV). The cyclic voltammetry (CV) profile reveals the absence of a redox peak, indicating the presence of a charge double-layer between the surface of activated carbon electrodes and electrolytes. The maximum specific capacitance, Cs value was obtained as 118.4 F/g at the sweep rate of 10 mV/s.

Structural, Electrical and Electrochemical Properties of Mg0.55Si1.9Al0.1Fe0.1(PO4)3 Ceramic Electrolytes

2017 ◽  
Vol 20 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Nurul Akmaliah Dzulkurnain ◽  
N. A. Mustaffa ◽  
N. S. Mohamed
Keyword(s):  
Electrochemical Properties ◽  
Ion Mobility ◽  
Sol Gel ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
X Ray Diffraction ◽  
Ionic Transference Number ◽  
Ceramic Electrolytes ◽  
Gel Technique ◽  
Mobile Ions

This study was undertaken to investigate the structural, electrical and electrochemical properties of Fe3+ substituted Mg0.55Si1.9Al0.1(PO4)3 compound synthesized by water-based sol–gel technique. X-ray diffraction showed that the compound crystallized in monoclinic crystalline phase with a space group of P1 21/c1. The sample sintered at 850 ˚C exhibited the highest conductivity of 1.42 × 10-6 S cm-1 at 373 K since it contained the highest number of mobile ions. It also exhibited the highest value of ion mobility, μ of 1.13 × 10-11 cm2 V-1 s-1 at ambient temperature which was attributed to the optimum size of migration channel as indicated by its unit cell volume. Linear sweep voltammetry result showed that the Mg0.55Si1.9Al0.1Fe0.1(PO4)3 was electrochemically stable up to 3.0 V. Meanwhile, its ionic transference number of 0.99 suggested that the majority of the mobile charge carriers were mainly to ions, expected to be Mg2+ ions.

Enhanced Photoelectrocatalytic Activity of Oriented Rutile TiO2 Nanorod Array Film through Nb Doping

2014 ◽  
Vol 1010-1012 ◽  
pp. 195-201
Author(s):  
Meng Lei Chang ◽  
Dong Chu Chen ◽  
Xiu Fang Ye ◽  
Xin Jun Li ◽  
Liang Peng Wu ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Nanorod Array ◽  
Rutile Phase ◽  
Electrode System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conductive Glass ◽  
Nb Doping ◽  
Oxidation Of Glucose

TiO2 nanorod array films with or without Nb doping grown directly on transparent conductive glass (FTO) were prepared by a facile hydrothermal method. The films were characterized by means of field emission scanning electron microscopy (FE-SEM) with energy-dispersive x-ray spectra (EDS), X-ray diffraction (XRD) and the X-ray photoelectron spectroscoy (XPS). The electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV) and transient photocurrent were investigated in a three-electrode system with TiO2 nanorod array film served as the photoanode. The photoelectrocatalytic activity of the films was evaluated by the oxidation of glucose under UV irradiation. The results show that both the pure and Nb-doped TiO2 nanorods perpendicularly grown on FTO substrate are rutile phase. The resistance of the TiO2 nanorod array photoanode is decreased significantly by Nb doping. The steady-state photocurrent (iss) for glucose oxidation at Nb-doped TiO2 nanorod array film is much higher than that at the pure one. The enhanced photoelectrocatalytic activity of the Nb-doped TiO2 nanorods could be attributed to the enhanced charge transport ability.

scholarly journals From Cellulose, Shrimp and Crab Shells to Energy Storage EDLC Cells: The Study of Structural and Electrochemical Properties of Proton Conducting Chitosan-Based Biopolymer Blend Electrolytes

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1526 ◽  
Author(s):  
Shujahadeen B. B. Aziz ◽  
Muhamad. H. H. Hamsan ◽  
Muaffaq M. M. Nofal ◽  
Saro San ◽  
Rebar T. Abdulwahid ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Ammonium Fluoride ◽  
Amorphous Region ◽  
Internal Resistance ◽  
Solid Polymer ◽  
Electrical Equivalent Circuit

In this study, solid polymer blend electrolytes (SPBEs) based on chitosan (CS) and methylcellulose (MC) incorporated with different concentrations of ammonium fluoride (NH4F) salt were synthesized using a solution cast technique. Both Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results confirmed a strong interaction and dispersion of the amorphous region within the CS:MC system in the presence of NH4F. To gain better insights into the electrical properties of the samples, the results of electrochemical impedance spectroscopy (EIS) were analyzed by electrical equivalent circuit (EEC) modeling. The highest conductivity of 2.96 × 10−3 S cm−1 was recorded for the sample incorporated with 40 wt.% of NH4F. Through transference number measurement (TNM) analysis, the fraction of ions was specified. The electrochemical stability of the electrolyte sample was found to be up to 2.3 V via the linear sweep voltammetry (LSV) study. The value of specific capacitance was determined to be around 58.3 F/g. The stability test showed that the electrical double layer capacitor (EDLC) system can be recharged and discharged for up to 100 cycles with an average specific capacitance of 64.1 F/g. The synthesized EDLC cell was found to exhibit high efficiency (90%). In the 1st cycle, the values of internal resistance, energy density and power density of the EDLC cell were determined to be 65 Ω, 9.3 Wh/kg and 1282 W/kg, respectively.

scholarly journals Study of electrical properties of a reduced graphene-oxadiazole-2-thiol (rGS) PVA polymer composite

2018 ◽  
Vol 27 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Emaad T Bakir Al-Tikrity ◽  
Ibrahim F Waheed ◽  
Sabah M Ali
Keyword(s):  
Electrical Properties ◽  
Room Temperature ◽  
Composite Films ◽  
Low Frequency ◽  
Covalent Bonding ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reduced Graphene ◽  
Tan Δ

This work reports the synthesis and characterisation of reduced graphene-1,3,4-oxadiazole-2-thiol (rGS) as a novel nanocompound derivative for graphene. The preparation was performed through a series of reactions starting from graphene oxide, followed by incorporation of different proportions of this nanocompound with poly(vinyl alcohol) (PVA), via non-covalent bonding, to afford the rGS/PVA polymer composites. The pure rGS compound, rGS/PVA composite films and pure PVA film were characterised by different techniques including infrared (Fourier transform infrared) spectroscopy, scanning electron microscopy and powder x-ray diffraction. The electrical properties of the composite films, involving dielectric constant, permittivity ( ε′), imaginary permittivity ( ε″), conductivity (σAC) and loss factor tan δ, were investigated. The measurements were performed at frequencies of (5kHz to 0.5 MHz) at room temperature. At low frequency, the dielectric permittivity ( ε′) and imaginary permittivity ( ε″) attained higher values in all cases, although with increasing frequency these values diminished rapidly. It was also found that the alternating current conductivity of the composites increased with increasing frequency.

scholarly journals Volcanic tremor and plume height hysteresis from Pavlof Volcano, Alaska

Science ◽  
2017 ◽  
Vol 355 (6320) ◽  
pp. 45-48 ◽  
Author(s):  
David Fee ◽  
Matthew M. Haney ◽  
Robin S. Matoza ◽  
Alexa R. Van Eaton ◽  
Peter Cervelli ◽  
...  
Keyword(s):  
North America ◽  
Structural Changes ◽  
Low Frequency ◽  
Volcanic Tremor ◽  
Geophysical Data ◽  
Time Varying ◽  
Volcanic Emissions ◽  
Plume Height ◽  
The Relationship

The March 2016 eruption of Pavlof Volcano, Alaska, produced an ash plume that caused the cancellation of more than 100 flights in North America. The eruption generated strong tremor that was recorded by seismic and remote low-frequency acoustic (infrasound) stations, including the EarthScope Transportable Array. The relationship between the tremor amplitudes and plume height changes considerably between the waxing and waning portions of the eruption. Similar hysteresis has been observed between seismic river noise and discharge during storms, suggesting that flow and erosional processes in both rivers and volcanoes can produce irreversible structural changes that are detectable in geophysical data. We propose that the time-varying relationship at Pavlof arose from changes in the tremor source related to volcanic vent erosion. This relationship may improve estimates of volcanic emissions and characterization of eruption size and intensity.

scholarly journals Plasticized Polymer Blend Electrolyte Based on Chitosan for Energy Storage Application: Structural, Circuit Modeling, Morphological and Electrochemical Properties

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1233
Author(s):  
M. H. Hamsan ◽  
Muaffaq M. Nofal ◽  
Shujahadeen B. Aziz ◽  
M. A. Brza ◽  
Elham M. A. Dannoun ◽  
...  
Keyword(s):  
Metal Complex ◽  
Electrochemical Impedance ◽  
Minimum Degree ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Sweep Rate ◽  
Degree Of Crystallinity ◽  
Maximum Conductivity ◽  
Eis Measurements ◽  
The Impact

Chitosan (CS)-dextran (DN) biopolymer electrolytes doped with ammonium iodide (NH4I) and plasticized with glycerol (GL), then dispersed with Zn(II)-metal complex were fabricated for energy device application. The CS:DN:NH4I:Zn(II)-complex was plasticized with various amounts of GL and the impact of used metal complex and GL on the properties of the formed electrolyte were investigated.The electrochemical impedance spectroscopy (EIS) measurements have shown that the highest conductivity for the plasticized system was 3.44 × 10−4 S/cm. From the x-ray diffraction (XRD) measurements, the plasticized electrolyte with minimum degree of crystallinity has shown the maximum conductivity. The effect of (GL) plasticizer on the film morphology was studied using FESEM. It has been confirmed via transference number analysis (TNM) that the transport mechanism in the prepared electrolyte is predominantly ionic in nature with a high transference number of ion (ti)of 0.983. From a linear sweep voltammetry (LSV) study, the electrolyte was found to be electrochemically constant as the voltage sweeps linearly up to 1.25 V. The cyclic voltammetry (CV) curve covered most of the area of the current–potential plot with no redox peaks and the sweep rate was found to be affecting the capacitance. The electric double-layer capacitor (EDLC) has shown a great performance of specific capacitance (108.3 F/g), ESR(47.8 ohm), energy density (12.2 W/kg) and power density (1743.4 W/kg) for complete 100 cycles at a current density of 0.5 mA cm−2.

Electrochemical Corrosion Characterization of As-Cast Mg-7Li Alloy

2012 ◽  
Vol 557-559 ◽  
pp. 64-67
Author(s):  
Jun Gang Li ◽  
Ying Lv ◽  
Hong Wei Wang ◽  
Zhao Jun Zhu ◽  
Zun Jie Wei ◽  
...  
Keyword(s):  
Electrochemical Impedance ◽  
Low Frequency ◽  
Electrochemical Corrosion ◽  
Frequency Region ◽  
X Ray Diffraction ◽  
High Frequency Region ◽  
Anode Dissolution ◽  
Electrochemical Corrosion Behavior ◽  
Capacitive Reactance

The electrochemical corrosion behavior of as-cast Mg-7Li alloy in 3.5wt% NaCl aqueous solution was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and electrochemical workstation. Results showed that the Ecorr and the Icorr of Mg-7Li alloy were -1.5857V and 2.235×10-4A/cm2, respectively. The cathode process was chiefly the hydrogen evolution reaction, and the corrosion rate of Mg-7Li alloy was mainly controlled by anode dissolution. The corrosion products on the alloy surface consisted of Mg(OH)2, Li2O2 and Al(OH)3. The electrochemical impedance spectroscopy (EIS) of Mg-7Li alloy contained two capacitive loops and one inductive loop. The inductance value increased to 250 ohm•cm-2 with a rise in frequency at low frequency region. The value of capacitive reactance decreased with increasing frequency at medium frequency. The capacitive reactance maintained the value of 50 ohm•cm-2 with increasing frequency at high frequency region.

scholarly journals High Proton Conducting Polymer Blend Electrolytes Based on Chitosan:Dextran with Constant Specific Capacitance and Energy Density

Biomolecules ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 267 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
M. H. Hamsan ◽  
Wrya O. Karim ◽  
M. F. Z. Kadir ◽  
M. A. Brza ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Energy Density ◽  
Specific Capacitance ◽  
Polymer Blend ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Ammonium Fluoride ◽  
Constant Current ◽  
Discharge Process ◽  
Charge Discharge

Polymer blend electrolytes based on chitosan: dextran (CS:Dext) incorporated with various amounts of ammonium fluoride (NH4F) with constant specific capacitance (12.4 F/g) and energy density over 100 cycles were prepared using a solution cast technique. The blend electrolyte samples exhibit broader amorphous humps in X-ray diffraction (XRD) spectra compared to pure CS:Dext film. The Fourier transform infrared (FTIR) study indicates the complex formation of the added ammonium salt with the polymer blend functional groups through the shifting and decrease in the intensity of FTIR bands. The impedance plots were used to determine the conductivity of the samples. The field emission scanning electron microscopy (FESEM) images support the conductivity behavior of the samples. The impedance plots were applied in the determination of the conductivity of the samples in which the relatively highest conductivity was gained to be 1 × 10−3 S/cm. The transference number measurement (TNM) of the conducting electrolyte was 0.88, which portrays the dominancy of ion in the conduction process. Linear sweep voltammetry (LSV) verified the chemical stability and showed it to be 1.7 V and an effective electrical double layer capacitor (EDLC) that is applicable in electrochemical devices. The performance of the EDLC cell was examined using both cyclic voltammetry and constant current charge–discharge techniques at ambient temperature. The semi-rectangular shape of the cyclic voltammetry (CV) plot and no redox peak was observed. The charge-discharge process of the fabricated EDLC is durable over 100 cycles with an equivalent circuit resistance and power density of 194.5 Ω and 428 W/kg, respectively. Two main outcomes, the specific capacitance and energy densities of 12.4 Farad/g and 1.4 Wh/kg, respectively, are almost constant over 100 cycles.

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