Measurements Of Electrical Properties Research Articles

Glycerol-treated polypropylene/carbon black nanocomposites: Analysis of electrical, rheological, thermal and mechanical properties

Electrically conductive nanocomposites based on polypropylene (PP) were prepared using carbon black (CB) nanoparticles via melt blending in the presence of glycerol and castor oil as hydroxyl functional dispersing aids and maleic anhydride–grafted polypropylene (MAgPP) as a compatibilizer. Initially, electrical conductivity of PP/CB nanocomposites with different dosages of both CB nanoparticles and dispersing aids were investigated through electrical analysis. Results indicated that castor oil had no beneficial effects on electrical conductivity. However, the efficiency of 3 wt% loading of glycerol was verified through measurements of electrical, rheological, thermal and mechanical properties as well as by morphological studies. The volume electrical conductivity value of PP nanocomposites containing 12 wt% CB significantly enhanced to 1.2 × 10−4 S/cm by adding 3 wt% glycerol in compared with nanocomposite without glycerol with the volume conductivity value of 1.8 × 10−6 S/cm. Incorporation of optimum amount of glycerol favoured the dispersion of nanofiller in the matrix which was confirmed by scanning electron microscopy observations, leading to higher conductivity due to better formation of conductive pathways within the matrix. Additionally, at the same concentration of CB nanofiller, samples treated with 3 wt% glycerol showed higher melting temperatures, storage modulus ( Gˊ), complex viscosity, tensile modulus and elongation at break. These findings indicate that adding an optimum amount of an efficient hydroxyl functional component like glycerol into PP/CB nanocomposite can be a promising way to enhance the electrically conductive performance while other properties could be maintained well or even improved.

Photocurrent performance and enhancement of opto-electronic properties of spray pyrolysis deposited ZnO thin films via V-doping

This study reports on the deposition of highly transparent conducting n-type zinc oxide (ZnO) thin films on FTO substrates, via an optimized doping process. Our work is focused on doping zinc oxide with vanadium (V) using spray pyrolysis technique and ensure the synthesis of nanoparticles-shaped ZnO, with an improved optical, microstructural and electrical properties for solar cells applications, as optical window material. Undoped and V-doped ZnO thin films, with careful optimized amounts (2, 4, 6 and 8 at.%), were grown at maintained 550∘C pre-heated substrate during the deposition process, which enables us to obtain nano-sized ZnO particles. We proved that 4 at.% is the optimum V content that enhances the crystallinity of the grown thin film noticeably. With an average transmittance of 80%, the deposited thin films revealed high transparency in the visible domain with a slight decrease in optical transmission which might result from additional scattering. UV-Visible analysis showed that increasing V amounts, a resulting decrease in the energy bandgap ([Formula: see text]) is obtained from 3.26[Formula: see text]eV to 3.17[Formula: see text]eV for 4 at.% of V content. Moreover, deep level defects in zinc oxide can be reduced with vanadium doping and consequently strengthen the UV emission. The UV emission peak intensity rises with increasing V-doping amount then decreases slightly at 8% of V content. The electrical properties measurements showed a decrease in resistivity from 2.8 10[Formula: see text][Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm to 0.9 10[Formula: see text][Formula: see text][Formula: see text][Formula: see text]⋅[Formula: see text]cm when doping with 4 at.% of V. The crucial effect of the V-doping of ZnO was also demonstrated via the enhancement of carrier mobility that attains 38.5[Formula: see text]cm2/V[Formula: see text]⋅[Formula: see text]s at the optimum vanadium content. The photocurrent analysis revealed much higher visible light absorption in the V-doped zinc oxide thin films than that of undoped film. The photocatalytic activity enhancements are attributed to the lower recombination rate of the photogenerated electron-hole pairs, the narrowed bandgap, yielding a higher photocatalytic performance.

Superior piezoelectricity in lead-free barium titanate piezoceramics

Since the 21st century, increasing environmental protection and human health concern have been the driving force to develop lead-free piezoelectric materials with enhanced performances, and phase engineering strategy has been validated to be a viable method in numerous methodologies. Here, we gained a superb d33∼(637 ± 30) pC/N in lead-free (1–x)(Ba0.93Ca0.07)(Sn0.08Ti0.92)O3-x(Sb0.5Li0.5)TiO3 [abbreviated as (1–x)BCST-xSLT, 0 ≤ x ≤ 0.4% (in mole)] piezoelectrics utilizing chemical doping. To illustrate the relationship among composition-structure-performance, microstructure characterization, electrical properties measurement, first-principles calculation, and phase-field simulations were performed. Atomic-resolved polarization mapping of z-contrast imaging manifests the ferroelectric three phases (RO–T) coexist at the nanoscale with nanoscale polarization switching among them. Theoretical calculations and simulations confirm that the high-density nano-domain boundary bridges the polyphase coexisting nano-domains, which makes the polarization reversal easy, thus significantly reducing the energy barrier and polarization anisotropy among different phases.

Dielectric and electrical properties measurement of BCTO and Co & V-doped BCTO synthesized via semi-wet route method

Dielectric and electrical properties measurement of BCTO and Co & V-doped BCTO synthesized via semi-wet route method

Enhanced gas sensing capabilities of diamond layers using Au nanoparticles

The nanocrystalline diamond (NCD) film reveals a unique combination of physical, chemical, and optoelectronic properties, which makes it a promising material for various sensing applications. To improve a gas sensor's response, selectivity, or reproducibility, its surface is often modified with specific terminations, functional groups or (bio)molecules, thin films, etc. In this work, the NCD surface modification was achieved by a) layer morphology variation using two different types of chemical vapor deposition (CVD) systems, b) top surface termination (H-NCD and O-NCD), and c) Au nanoparticles (Au NPs). The properties of each structure are measured, compared and subsequently evaluated. The electrical properties (resistance changes) are measured for two types of active gas (oxidizing gas NO2 and reducing gas NH3) in a temperature range from 22 °C to 125 °C. Neutral synthetic air (80 % nitrogen and 20 % oxygen) was applied for flushing and resetting the sensors. Thin film fabrication, surface analysis (scanning electron microscopy and Raman spectroscopy), and measurement of electrical properties are described. Surface morphology greatly influences gas response because a large active surface area (higher roughness or 3D-like surface) enhances interaction with gas molecules. While the termination of the NCD with hydrogen is essential for the functionality of the gas sensor, the Au NPs further enhanced the dynamic response of the sensor and magnitude.

Removing of cationic dyes using self-cleaning membranes-based PVC/nano-cellulose combined with titanium aluminate

This research used the phase inversion approach to construct polyvinyl chloride nanocellulose@titanium aluminate nanocomposite membranes (PVC/NC@TALCM) to adsorb and filter dye from wastewater. FTIR, XRD, and SEM were used to determine the adsorptive nanocomposite membrane that had been synthesized. The thermal and electrical properties measurements were carried out using a static system. The influence of several adsorbent dosages, pH, and dye concentrations on the nanocomposite membrane’s adsorption ability was investigated. Using a dead-end filtration system, the PVC-NC@TALCM was evaluated as a pressure filtration membrane system. It was found that 98.6% of MB dye was removed by PVC-NC@TALCM membrane, which was loaded with 5% titanium aluminate at pH 10. The kinetic adsorption studies indicated that the adsorption of MB onto the PVC-NC@TALCM nanocomposite membrane obeys pseudo-second-order that indicates the chemosorption process. The isotherm data were described using Freundlich and Langmuir models, and the Freundlich isotherms were shown to be more closely match the experimental data than the Langmuir model. Finally, the PVC-NC@TALCM nanocomposite membrane was economical, environmentally friendly, and self-cleaning.

Novel n‐type Zintl phase thermoelectric materials: The Ca5−xRExAl2Sb6 (RE = Pr, Sm) system

AbstractTwo novel n‐type Zintl thermoelectric materials of Ca4.97(1)Pr0.03Al2Sb6 and Ca4.94(2)Sm0.06Al2Sb6 were synthesized with the addition of two types of trivalent rare‐earth metals dopants and characterized by powder and single crystal x‐ray diffraction analyses. Two title compounds adopted the orthorhombic Ca5Ga2As6‐type phase and contained seven crystallographically unique atomic positions including one particular Ca/Pr or Ca/Sm mixed‐site. The crystal structure can be described as a combination of the one‐dimensional (1D) infinite chains and the cationic elements in between the 1D chains. Electrical transport property measurements proved that Ca4.97(1)Pr0.03Al2Sb6 and Ca4.94(2)Sm0.06Al2Sb6 were indeed novel n‐type Zintl phase semiconductors with the maximum electrical conductivities of 69.51 and 75.51 S/cm at 846 K and the Seebeck coefficients of −43.26 and − 29.00 μV/K at 703 K, respectively. Density functional theory calculations proved that the successful n‐type doping should be attributed to a small margin of slight antibonding states near EF on the Sb1Sb1 crystal orbital Hamilton population (COHP) curve.

Enhancing Dielectric and Thermal Performances of Synthetic-Ester Insulating Oil via Blending With Natural Ester

Synthetic ester and blended insulating oils have attracted widespread attention owing to their great potential on performance enhancement because of the high capacity with tailorable molecular structure and mixable components. In this work, natural ester insulating oil (FR3) is blended into the synthetic tetra-ester insulating oil (KA) via mixing and oscillating. The physicochemical and electrical property measurements of the ester blends indicate the flash point, fire point, and AC breakdown voltage of KA are capable to be increased, and the dissipation factor of KA is reduceable by the addition of FR3. As expected, a series of physicochemical properties of the ester blends follow a quasi-linear relationship with the variation (in vol%) of FR3. However, the flash point (closed cup) is verified with high nonlinearity according to the results of thermogravimetric-derivative and thermogravimetric-differential scanning calorimetry (TG-DSC) tests in nitrogen. The optimized ester blend (85 vol% (KA):15 vol% (FR3)) is typically manifested by high flash point (260°C), low pour point (-51°C), low dissipation factor (1.44%), high AC breakdown voltage (76.5 kV), and high onset temperature of DSC either in nitrogen (229.99°C) or in the air (272.05°C). The activation energy is analyzed based on the Arrhenius equation, dissipation factor, and resistivity values in order to recognize the optimum ratio of the ester blends.

Electrical properties of tissues from a microscopic model of confined electrolytes

Objective. In the presence of oscillatory electric fields, the motion of electrolyte ions in biological tissues is often limited by the confinement created by cell and organelle walls. This confinement induces the organization of the ions into dynamic double layers. This work determines the contribution of these double layers to the bulk conductivity and permittivity of tissues. Approach. Tissues are modeled as repeated units of electrolyte regions separated by dielectric walls. Within the electrolyte regions, a coarse-grained model is used to describe the associated ionic charge distribution. The model emphasizes the role of the displacement current in addition to the ionic current and enables the evaluation of macroscopic conductivities and permittivities. Main results. We obtain analytical expressions for the bulk conductivity and permittivity as a function of the frequency of the oscillatory electric field. These expressions explicitly include the geometric information of the repeated structure and the contribution of the dynamic double layers. The low-frequency limit of the conductivity expression yields a result predicted by the Debye permittivity form. The model also provides a microscopic interpretation of the Maxwell–Wagner effect. Significance. The results obtained contribute to the interpretation of the macroscopic measurements of electrical properties of tissues in terms of their microscopic structure. The model enables a critical assessment of the justification for the use of macroscopic models to analyze the transmission of electrical signals through tissues.

A study on Sm2O3-doped Ba(Zr0.02Ti0.98)O3 ceramics for sensor applications

ABSTRACT Ba(Zr0.02Ti0.98)O3 (BZT) samples with various weight percentages of Sm2O3 (0.02–0.06) were synthesized and calcined at 1100°C for 4 h. Circular pellets were prepared using calcined powders and sintered at 1450°C for 2 h. The sintered and poled samples were used for the measurement of various electrical properties. Maximum piezoelectric charge constant (d 33) of 372 pC/N obtained for 0.02 wt.% Sm2O3-doped BZT. Dielectric constant (K = 15,855) at 100 Hz was found maximum for this composition at Curie temperature (T c) of 125°C. Scanning electron microscopy (SEM) study revealed a decrease in grain size with an increase in Sm2O3 content. Largely, a lower concentration of Sm2O3-doped BZT compositions with higher d 33 could be suitable for vibration sensor and accelerometer applications.

Optimization of PVDF-TrFE Based Electro-Conductive Nanofibers: Morphology and In Vitro Response.

In this study, morphology and in vitro response of electroconductive composite nanofibers were explored for biomedical use. The composite nanofibers were prepared by blending the piezoelectric polymer poly(vinylidene fluoride-trifluorethylene) (PVDF-TrFE) and electroconductive materials with different physical and chemical properties such as copper oxide (CuO), poly(3-hexylthiophene) (P3HT), copper phthalocyanine (CuPc), and methylene blue (MB) resulting in unique combinations of electrical conductivity, biocompatibility, and other desirable properties. Morphological investigation via SEM analysis has remarked some differences in fiber size as a function of the electroconductive phase used, with a reduction of fiber diameters for the composite fibers of 12.43% for CuO, 32.87% for CuPc, 36.46% for P3HT, and 63% for MB. This effect is related to the peculiar electroconductive behavior of fibers: measurements of electrical properties showed the highest ability to transport charges of methylene blue, in accordance with the lowest fibers diameters, while P3HT poorly conducts in air but improves charge transfer during the fiber formation. In vitro assays showed a tunable response of fibers in terms of viability, underlining a preferential interaction of fibroblast cells to P3HT-loaded fibers that can be considered the most suitable for use in biomedical applications. These results provide valuable information for future studies to be addressed at optimizing the properties of composite nanofibers for potential applications in bioengineering and bioelectronics.

Evaluation of conductive smart composite polymeric materials for potential applicationsin structural health monitoring and strain detection

The presented work collects results from the evaluation of electrical response to mechanical deformation and formation of defects presented by different polymeric based composite materials with potential for applications in Structural Health Monitoring and Strain Detection. With the aim of showing the variety of key materials in sectors like civil aviation, wind energy, automotive or railway that present this ability, specimens of very different nature have been analyzed: a) thermoplastic commercial 3D printing filaments loaded with carbonic fillers; b) epoxy resin loaded with Carbon Nanotubes and c) long carbon fiber reinforced resin composite. Measurements of electrical properties of these materials were taken to evaluate their capability to detect the presence of structural defects of different sizes as well as its spatial location. On the other hand, simultaneous measurements of electrical resistivity and mechanical strain during tensile tests were performed to analyze the potential of materials as strain detectors. All composites studied have shown a positive response (modification of electrical performance) to external mechanical stimulus: induced damage and deformations.Graphical

A review of electrical properties of biodiesel and its blends: experimental data, prediction models and applications

AbstractBiodiesel is widely used pure or mixed with diesel fossil fuel in diesel engines. Standards for determining biodiesel quality establish limits for the values of several physicochemical properties. However, the procedures to determine many properties are time‐consuming and demand specialized personnel and expensive equipment. Other methods to characterize biodiesel, such as electrical methods, are particularly interesting. Measurements of electrical properties (permittivity and conductivity) give valuable information about biodiesel, its feedstocks, and its blends with fossil fuel diesel, and solve the usual cost and time drawbacks. This work aims to present a thorough and systematic review of the literature on applications of electrical properties measurements of biodiesel, its feedstocks, and mixtures with other fuels. An overview of the experimental data, typical ranges of values, prediction models, and applications is presented and analyzed in detail, emphasizing blends of biodiesel with fossil fuel diesel. Correlations with important properties (kinematic viscosity, methanol content) are reviewed. Applications include transesterification monitoring, biodiesel aging, the detection of contaminants and electromagnetic heating. This research aimed to determine whether electrical properties are a valuable tool for the biodiesel industry, and what applications may be realized in light of current scientific development. It was determined that, in the current state of research, permittivity measurements could be used to accurately determine the amount of diesel and biodiesel in mixtures. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd.

Intrinsic thermal stability enhancement in n-type Mg3Sb2 thermoelectrics toward practical applications

Mg3Sb2-based Zintl compounds show great promise for thermoelectric power generation due to their favorable properties, such as high thermoelectric performance over a wide range of temperatures, low cost, and mechanical robustness. However, their practical application is severely impeded by the low thermal stability induced by significant Mg loss at elevated temperatures. Here, with the goal to intrinsically enhance the thermal stability of Mg3Sb2-based materials, a strategy of Mn doping at the Mg site is investigated and is found to be effective. In addition to having a high average zT, Mn-doped Mg3Sb1.5Bi0.5 exhibits negligible variation in electrical performance throughout a 40-hour continuous electrical properties measurement at 673 K. Microstructure and composition analyses verify the high structural stability of the Mn-doped sample following the long-term in situ measurement. Density functional theory (DFT) calculations show that the enhanced thermal stability of the Mn-doped compound results from the stronger bonding between Mn and Mg atoms in comparison to the Mg-Mg bonds, which can significantly suppress the formation of Mg vacancies. This study demonstrates a novel approach to the development of reliable thermoelectric materials with both a high zT and intrinsically improved thermal stability for applications.

Effect of calcium addition on microstructure, structure, and electrical properties of SrTiO3-based materials synthesized by citrate and solid-state reaction method

Materials with a general formula Sr1-xCaxTiO3 (where x = 0.0; 0.2; 0.4; 0.6; 0.8; 1.0) were obtained by two different synthesis routes: wet chemical method and conventional solid-state reaction. The effect of the synthesis method and the calcium content on the properties of the synthesized materials was evaluated. All materials were sintered at 1400 °C and tested for structural, microstructural, and electrical properties. X-ray diffraction analysis showed a decrease in the symmetry of the perovskite structure (cubic → tetragonal → orthorhombic) and a decrease in the cell volume of the perovskite structure phases with an increase in the Ca amount introduced into the system, regardless of the applied synthesis method. Also, the materials obtained by the citrate method had a smaller grain size compared to the materials synthesized by the solid-state method. However, for materials synthesized by both methods the increase of grain size with increasing calcium amount was observed. Moreover, the effect of calcium content on the porosity of the materials obtained by the citrate method was observed while for materials obtained by the solid-state reaction this parameter was generally not affected by Ca amount. The results of electrical properties measurements carried out in the air atmosphere indicate the ionic conductivity in Sr1-xCaxTiO3 materials irrespective of the applied synthesis method.

Combined Additive and Laser-Induced Processing of Functional Structures for Monitoring under Deformation

This research introduces a readily available and non-chemical combinatorial production approach, known as the laser-induced writing process, to achieve laser-processed conductive graphene traces. The laser-induced graphene (LIG) structure and properties can be improved by adjusting the laser conditions and printing parameters. This method demonstrates the ability of laser-induced graphene (LIG) to overcome the electrothermal issues encountered in electronic devices. To additively process the PEI structures and the laser-induced surface, a high-precision laser nScrypt printer with different power, speed, and printing parameters was used. Raman spectroscopy and scanning electron microscopy analysis revealed similar results for laser-induced graphene morphology and structural chemistry. Significantly, the 3.2 W laser-induced graphene crystalline size (La; 159 nm) is higher than the higher power (4 W; 29 nm) formation due to the surface temperature and oxidation. Under four-point probe electrical property measurements, at a laser power of 3.8 W, the resistivity of the co-processed structure was three orders of magnitude larger. The LIG structure and property improvement are possible by varying the laser conditions and the printing parameters. The lowest gauge factor (GF) found was 17 at 0.5% strain, and the highest GF found was 141.36 at 5%.

High-Efficiency Single-Cell Electrical Impedance Spectroscopy.

Single-cell impedance measurement is label free and noninvasive in characterizing the electrical properties of single cells. At present, though widely used for impedance measurement, electrical impedance flow cytometry (IFC) and electrical impedance spectroscopy (EIS) are used alone for most microfluidic chips. Here, we describe high-efficiency single-cell electrical impedance spectroscopy, which combines in one chip the IFC and EIS techniques for high-efficiency single-cell electrical property measurement. We envision that the strategy of combining IFC and EIS provides a new thought in the efforts to enhance the efficiency of electrical property measurement for single cells.

Multiphysics Experimental Approaches for Insight into the Hydrogen Bonded Structures of Ethylene Glycol and Glycerol Mixtures toward Green Solvent Technology

Alcohols and their mixtures are credited most important polar solvents for advances in pharmaceutical, chemical,biological, thermal, and material technologies. A rigorous study for the characterization of hydrogen bonded heterogeneousintermolecular structures that formed in a mixed solvent based on alcohols containing two and three hydroxyl groupsmolecules is crucial to specific technological and industrial applications. Hence, in this work, the multiphysics experimentalapproaches including the measurements of dielectric, electrical, viscous, acoustic, thermal, and optical properties are appliedand analyzed to confirm the behaviour of hydrogen bonded molecular structures of ethylene glycol (EG; dihydric alcohol)with glycerol (Gl; trihydric alcohol) over the entire concentration range of EG+Gl mixtures at 298.15 K. The static dielectricpermittivity, direct current electrical conductivity, low frequency relaxation time, and refractive index values of the EG+Glmixtures are reported. Additionally, dynamic viscosity, density, ultrasound velocity, adiabatic compressibility,intermolecular free length, acoustic impedance, free volume, Rao’s constant, Wada constant, and viscoacoustic relaxationtime of the EG+Gl mixtures are determined, and also explored their significance to these alcohols molecular interactions.Ultraviolet-visible range absorbance behaviour of the alcohol mixtures is characterized in detail and confirmed theelectronic transitions at higher energy ultraviolet radiations. The detailed analysis of all the experimental results along withthe consideration of excess properties evidenced the formation of heterogeneous intermolecular hydrogen bonded structuresin these Newtonian-type alcohols mixtures. A small to adequate variation in the thermodynamical and other investigatedproperties with the concentration variation showed that the EG+Gl mixture can be optimized as a green solvent according tothe prerequisite properties for huge advances in soft condensed matter technologies.

Tailoring the Structural, Optical and Electrical Properties of Zinc Oxide Nanostructures by Zirconium Doping

Owing to its low resistivity, high transmittance, and tunable optical band gap, ZnO is of great interest for optoelectronic applications. Herein, the sol–gel technique was used to synthesize un-doped and zirconium-doped zinc oxide (ZZO) nanostructures with different concentrations of Zirconium (Zr). X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, and photoluminescence (PL) measurements were used to investigate the influence of Zr doping on the structural, optical, and electrical properties of developed nanostructures. XRD and SEM confirmed the increase in crystallite size with increasing concentrations of Zr. Raman analysis indicated the presence of oxygen vacancies in synthesized nanostructures. UV-Vis spectroscopy illustrated the blue shift of band gap and red shift of the absorption edge for ZZO nanostructures with increasing concentrations of Zr. For the measurement of electrical properties, the spin-coating technique was used to deposit un-doped and Zr-doped ZnO layers of ~165 nm thickness. The four-probe-point (4PP) method illustrated that the doping of Zr caused a reduction in electrical resistance. Hall Effect measurements showed a high value, 3.78 × 1020 cm−3, of the carrier concentration and a low value, 10.2 cm2/Vs, of the carrier mobility for the Zr-doped layer. The high optical transmittance of ~80%, wide band gap of 3.51 eV, low electrical resistivity of 1.35 × 10−3 Ω·cm, and maximum carrier concentration of 3.78 × 1020 cm−3 make ZZO nanostructures one of the most promising candidates for the application of transparent conductive oxide (TCO) in optoelectronic devices.

Revealing the intrinsic transport properties of antiperovskite Sr3SnO thin films

A topologically non-trivial band structure and reports of superconductivity have motivated significant investigation into the transport properties of the antiperovskite oxide Sr3SnO. Phase-pure films of Sr3SnO can be grown by molecular beam epitaxy, but they do not have the required extremely high hole-doping densities (>1 × 1021 cm−3) for which superconductivity has been observed in bulk materials. To date, high hole-doping densities have been achieved via inducing strontium deficiency, which inevitably results in impurity phases. Here, we show that indium acts as an effective hole dopant in Sr3SnO and can be used to achieve high hole doping densities in stoichiometric films. Films with carrier densities as high as 1.5 × 1021 cm−3 remain non-superconducting. We, therefore, suggest that Sr3SnO is probably not an intrinsic superconductor. A second question addressed in this work is the measurement of the intrinsic electrical transport properties of Sr3SnO, given its rapid degradation in air. We show that even in inert atmospheres, reducing the time needed for establishing electrical contacts and protecting the Sr3SnO film result in improved electrical properties. We demonstrate low carrier density films (4 × 1018 cm−3) with carrier mobilities of 400 cm2 V−1 s−1 at 10 K.