Papers by Keyword: Conductivity

Abstract: This abstract focuses on the green synthesis of copper nanoparticles (CuNPs), a significant class of nanoparticles with diverse applications. Green synthesis methods, such as plant extracts, microbial-mediated synthesis, and eco-friendly reducing agents, offer several advantages including low cost, scalability, and reduced environmental impact. Utilizing natural sources such as plant extracts rich in phytochemicals and microorganisms capable of reducing metal ions, CuNPs can be synthesized efficiently under mild conditions without the need for rigid chemicals. In recent years, the synthesis of nanoparticles has garnered significant attention due to their unique properties and diverse applications in various fields, including catalysis, electronics, medicine, and environmental remediation. Among the different methods available for nanoparticle synthesis, green synthesis has emerged as a promising approach due to its eco-friendly nature and potential for large-scale production without harmful by-products. Copper nanoparticles (CuNPs) have gained particular interest owing to their exceptional properties and wide-ranging applications. This work explores the green synthesis of copper nanoparticles, focusing on the principles, methods, characterization techniques, and applications of these environmentally nanomaterials.

Abstract: The main objective of this study is to optimize the reverse osmosis process in order to ensure the potabilization of water from the Oued Oum Er-Rbia, by determining the most influential parameters. To the best of our knowledge, this is the first study to apply daily PCA-based monitoring on Oued Oum Er-Rbia’s raw water to optimize membrane operation under Moroccan field conditions.To better understand the interactions between quality and hydraulic parameters influencing membrane performance, data were collected from Oued Oum Er-Rbia over multiple seasons. The parameters monitored included turbidity, salinity, temperature, and Silt Density Index (SDI), all known to affect fouling and pretreatment requirements.

Abstract: Polymer-metal hybrid nanocomposites have garnered significant attention in recent years due to their exceptional electrical and dielectric properties, which find applications in a wide range of industries, including electronics, energy storage, and advanced materials. This review article provides a comprehensive overview of the current state-of-the-art in the field of polymer-metal hybrid nanocomposites, with a particular focus on their electrical and dielectric properties. The first section of the review delves into the synthesis and fabrication techniques employed to create these nanocomposites, highlighting the importance of controlling the dispersion and distribution of metal nanoparticles within the polymer matrix. Various approaches, such as in-situ polymerization, melt mixing, and electrospinning, are discussed in detail, along with their respective advantages and limitations.The subsequent sections explore the influence of metal nanoparticles on the electrical conductivity and dielectric constant of the nanocomposites. The role of factors such as nanoparticle size, shape, and concentration in determining these properties is thoroughly examined. Moreover, the impact of metal surface modifications and the choice of polymer matrix on enhancing electrical and dielectric performance are also addressed. In addition to discussing fundamental aspects, this review highlights practical applications of polymer-metal hybrid nanocomposites in the development of high-performance capacitors, sensors, electromagnetic shielding materials, and flexible electronics. The potential for these materials to revolutionize various technological sectors is discussed, emphasizing their role in advancing miniaturization, energy efficiency, and durability. Furthermore, the review outlines current challenges and future prospects in the field, including the need for a deeper understanding of the underlying mechanisms governing electrical and dielectric behavior in these nanocomposites. Emerging trends such as the incorporation of 2D materials and the development of multifunctional hybrid systems are also explored, hinting at exciting avenues for further research and innovation. In conclusion, polymer-metal hybrid nanocomposites offer a promising platform for tailoring electrical and dielectric properties to meet the demands of modern technology. This review serves as a valuable resource for researchers, engineers, and scientists seeking to explore the potential of these materials and drive advancements in the field of electrical and dielectric engineering.

Abstract: In this study, LiTi₂(PO₄)₃ (LTP) was synthesized by the addition of lithium fluoride (LiF) of 0 %, 5 %, and 10 wt.%. A wet solid-state reaction method is applied by mixing Li₂CO₃, TiO_2, and NH₄H₂PO₄ into a ball mill, then calcined at 900^o C for 12 hr. XRD pattern of Fluoride-doped LTP is indexed and found in two phases. First is the Nasicon phase (LiTi₂(PO₄)₃) with rhombohedral structure, and second, the Olivine phase (LiTiPO5) with orthorhombic structure at the addition of 5 % and 10 wt. % of LiF. The higher LiF decreases the cell volume while the crystallite size, particle size, and material density increase. The morphology of the Fluoride-doped LTP is increasingly homogeneous and more rectangle-shape. LTP 2, adding 10 wt. % of LiF, has high ionic conductivity at 4.77 10^-4 S cm^-1 as a promising candidate material for solid-electrolyte of lithium-ion battery.

Abstract: This work deals with an adaptable water reactor design built from different modules as a basis for research. These modules are selected according to the application and are used for sensor related cleaning and supporting tasks. For example, to produce a specific water quality or for pharmaceutical applications. Sensor related modules are used to measure various parameters such as temperature, TOC, flow parameters and others. In addition to simple membrane filter modules, UV-C disinfection and experimental modules are integrated into the setup. Modules for pumping processes, for power supply such as solar, for control tasks and the connection systems of water and electricity between modules are also outlined. This system is described on the basis of scientific examples that use this system. In more detail the modules for temperature, TOC measurement, and UV-C disinfection as well as the supply and control modules are shown.

Abstract: Mixing conducting particles in cement present various applications in electromagnetic shielding and in-situ inspection of structures. In this study, graphite was incorporated in cement paste at varying concentrations which enhanced its EM shielding. The samples were characterized using Terahertz Time-Domain Spectroscopy (THz-TDS) to determine its optical properties and calculate for the conductivity. The Ultraviolet-Visible (UV-Vis) spectroscopy was also used to characterize the sample to confirm the variation of graphite content which showed small peaks at 258 nm caused by the excitation of π electrons in the graphitic structure. The refractive index, absorption coefficient and conductivities were determined from the amplitudes and phase difference obtained in the frequency domain. The spectral cut-off in the THz region decreases with increasing graphite content due to THz absorption of graphite. The THz refractive index appeared to be not frequency-independent while the absorption coefficient showed a power-law behavior. The THz conductivities were calculated and was found to be proportional to the graphite content. This is attributed to an increase in the conducting network of cement paste and increase in the charge carriers in the insulating cement matrix.

Abstract: The conventional solid-state reaction method was used to prepare the lead-free solid-solution (1-x)Ba_0.06(Na_0.5Bi_0.5)_0.94TiO₃-xNaTaO₃; 0 ≤ x ≤ 1. X-ray diffraction analysis of all the compositions of the series confirmed the solid solution’s successful formation. The electrical impedance and conductivity of the material were studied using the impedance spectroscopy method at temperatures ranging from room temperature to 500^○C. For the Ba_0.06(Na_0.5Bi_0.5)_0.94TiO₃ rich compositions ac conductivity increased with frequency at all temperatures, whereas for the NaTaO₃ rich compositions ac conductivity exhibited a frequency-independent behaviour. As the amount of NaTaO₃ incorporated into the compound Ba_0.06(Na_0.5Bi_0.5)_0.94TiO₃ was increased, a transition occurred in the electrical impedance, specifically, the impedance values shifted from low to high. A theoretical model based on correlated barrier hopping (CBH) has been used to explain the conduction mechanism in these solid solutions.

Abstract: Iron substituted Lead zirconate titanate nanoparticles Pb (Zr_0.52Ti_0.48) _1-x Fe_xO_3-x (PZTFx) (for (x=0.00, 0.025, 0.05, 0.075, 0.10, 0.15 and 0.20) was prepared using the sol-gel route in the morphotropic phase boundary (MPB) region. The X-ray diffraction data revealed the formation of both rhombohedral and tetragonal structures. The microstructural properties of the compounds were examined through the scanning electron microscopy (SEM) technique. The impedance spectroscopy and conductivity spectroscopy were carried out over a wide range of temperatures (RT–400°C) and frequencies (100 Hz–2 MHz) to investigate the grain and grain boundary effect on the electrical properties of PZTFx. The complex impedance analysis data have been presented in the Nyquist plot which is used to identify the corresponding equivalent circuit and fundamental circuit parameters. Cole– Cole plots indicate Debye-type dielectric relaxation and the grain boundaries resistance is dominant at room temperature. The Nyquist plot showed the negative temperature coefficient of resistance (NTCR) character of PZTFx ceramics. The dielectric properties of (PZTFx) ceramics as a function of temperature are studied and displayed a resonance phenomenon for all samples. Temperature-dependent conductivity behavior indicated an Arrhenius type of thermally activated process in the low-temperature region. Activation energy has been calculated from the temperature-dependent DC electrical conductivity measurements for all the samples.

Abstract: Property investigation of co-doped 4 mol% scandia and 4 mol% yttria zirconia (Sc_0.08Y_0.08Zr_0.84O_1.92 or 4Sc4YSZ) synthesized via solid-state reaction (SSR) and all-alkoxide sol-gel (SG) method as precursor powders with LSM as composite electrode was conducted. The microstructure and morphology of the precursor powders and resulting LSM-4Sc4YSZ bulk composite electrodes were characterized. The results revealed that the 4Sc4YSZ was successfully synthesized via SG with more distinct cubic phases and finer particles than 4Sc4YSZ prepared via SSR. A more homogeneous and uniform distribution for LSM-4Sc4YSZ SG was also observed with a porosity of 30.65%. Moreover, using electrochemical impedance spectroscopy (EIS), the LSM-4Sc4YSZ SG revealed a total conductivity of 0.158 S/cm at 700 °C with an activation energy of 0.018 eV.

Abstract: This research uses the Solid State method to produce LiNi_xFe_1-xPO₄ /C Composite Materials with variation Ni ion doping are x= 0.01, 0.02, and 0.03, Characterization was carried out using XRD, PSA, SEM and EIS. The results of XRD analysis showed that LiFePO₄, Li₃Fe₂PO₄ and Fe₂O₃ phases were formed. The conductivity test results show that the conductivity of the LFP/C precursor is 10.24x10^-4 S/cm, the LiNi_0.01Fe_0.99PO₄/C precursor is 7.75 x10^-4 S/cm, the LiNi_0.02Fe_0.98PO₄/C precursor is 10.334 x10^-4 S/cm, and the precursor LiNi_0.03Fe_0.97PO₄/C was 4.87 x10^-4 S/cm . With the highest conductivity value at LiNi_0.02Fe_0.98PO₄/C precursor.