Discharge Technique Research Articles

In vitro antibacterial properties of MoO3/SiO2/Ag2O nanocomposite coating prepared by double cathode glow discharge technique

To obtain a self-disinfecting surface to combat nosocomial infections, in situ synthesis of the MoO3-SiO2-Ag2O nanocomposite antibacterial coating was prepared onto Ti–6Al–4V substrate via a double cathode glow discharge technique conducted in a Ar + O2 gas mixture. The phase composition, microstructure and chemical structure of the as-prepared coating were systematically characterized by means of a series of microscopic examination methods. The microstructure of the coating exhibited an amorphous/nanocrystalline architecture, and both the MoO3 and Ag2O crystallites were evenly embedded in an amorphous SiO2 matrix. Photocatalytic activities of the coating were evaluated by photodegradation of rhodamine B (RhB) dye. The results showed that the introduction of Ag2O enhanced photocatalytic activity of the MoO3-SiO2 nanocomposite coating. In vitro antibacterial activity of the MoO3-SiO2-Ag2O coating against Gram-negative bacteria, Gram-positive bacteria and fungi were investigated and compared with that of the MoO3-SiO2 coating under both dark and visible light conditions. The MoO3-SiO2-Ag2O coating possessed higher bactericidal activities than the MoO3-SiO2 coating, due to the combined effects of surface hydrophobicity, the release of Ag+ ions, surface acidic reaction and photocatalytic activity.

Synthesis of hexagonal nanozinc by arc discharge for antibacterial water treatment

The arc discharge technique with some modifications was carried out to synthesize a high percentage of metallic zinc (Zn) nanoparticles (ZnNPs) with a high degree of structural perfection. The antibacterial potentials of the synthesized ZnNPs against common waterborne bacterial pathogens were compared as a more applicable disinfection method than conventional ones. The obtained characteristics (X-ray diffraction, energy-dispersive X-ray spectroscopy and transmission electron microscopy) of the prepared ZnNPs indicated their perfect hexagonal surface shape and the high purity of the zinc metal. Moreover, the prepared nanoparticles showed significant bacteriostatic and bactericidal effect against the various tested bacteria. The findings of this study support the use of ZnNPs as a strong antibacterial agent in water desalination plants and manufacturing of water filters. Moreover, the findings suggest the use of the arc discharge technique for preparing more effective nanometals with different shapes and high purity.

Solid Lipid Nanoparticles (SLN) as a Novel Drug Delivery System: A Theoretical Review

The introduction of solid Lipid Nanoparticles (SLN) for the first time in late 1991 to be a substitute transporter system to what known old colloidal carriers, like emulsions, liposomes, and polymeric micro- and nanoparticles. SLN has merits and potentialities of Classical structures except avoiding some of their common and known disadvantages. This paper reviews SLN production techniques, The integration of drugs, the capacity to load and the release of drugs, with particular emphasis on drug discharge techniques. Issues relating to the introduction of the SLN into the pharmaceutical industry, like the excipients position. From the very beginning a special and wide interest paid to Lipid nanoparticles (LNPs) during the last decade. Nanostructured lipid transporters strong lipid nanoparticles (SLNs) become the most two essential forms of nanoparticles formed from lipids. SLNs were designed to be able to overcome certain restrictions types of colloidal vectors, like liposomes, emulsions, and polymeric nanoparticles as they possess bright sides like strong discharge profile and guided distribution of drugs with the most perfect physical health. NLCs will amend the SLNs in the next generation of lipid nanoparticles in a way that enhances stability, safety and capacity loading. This paper focuses on methods to reduce toxic effects using advanced production techniques such as homogenization and solvent evaporation. As it facilitates way for the solid lipid nanoparticles approval as novel or targeted medication distribution system by using several recent analytical techniques like electron microscopy and dynamic light scattering (DLS), differential scanning calorimetry (DSC), nuclear magnetic resonance, atomic force microscopy and their evaluation parameters concurrent with the application. Conclusion • Solid lipid nanoparticles (SLNs) represent a transport system alternative to conventional colloidal carriers. • SLNs combine the advantages of traditional and modern systems if some of their major difficult proceedings are eliminated. • SLN production techniques include drug incorporation, drug loading and release capacity, with a special focus on drug release methods. • SLNs as novel system and targeted drugs delivery method through using recent techniques.

Syntheses and characterizations of GO/Mn3O4 nanocomposite film electrode materials for supercapacitor applications

We have, in this study; used simple, in-expensive and environmentally-friendly successive ionic layer adsorption and reactions (SILAR) deposition procedure to successfully grow GO/Mn3O4 thin film electrode materials. The deposited films were examined for their surface morphology using scanning electron microscopy (SEM) while its morphology and structure was confirmed using transmission electron microscopy (TEM) and selected area electron diffractometry (SAED) respectively. X-ray diffraction (XRD) was used to study their structural properties while their supercapacitive studies were obtained using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. All deposited films were scanned in 1 M solution of Na2SO4 electrolyte. The SEM images of the deposited films revealed highly porous interconnected morphology with Mn3O4 densely dispersed among graphene oxide (GO). Individual peaks of Mn3O4 and GO compounds indicating uniform spread of Mn3O4 inside the porous matrix of GO were observed from the XRD. Mn3O4 nanograins well-dispersed on the surface were further confirmed through the TEM images while bright concentric rings confirming the polycrystalline nature of the films were observed from SAED images. The film deposited at 40 cycles yielded the maximum specific capacitance of 532.54 Fg−1at 5 mVs−1 scan rate. The results of the electrochemical studies show that the GO/Mn3O4 composite films synthesized by SILAR could be a promising material for supercapacitors.

STUDY THE OPTICAL PROPERTIES OF THE VARIOUS DEPOSITION SOLUTIONS OF ZnO NANORODS GROWN ON GLASS SUBSTRATE USING CHEMICAL BATH DEPOSITION TECHNIQUE

In this study, two-step chemical bath deposition (CBD) technique has been employed for the fabrication of Zinc Oxide (ZnO) nanorods at low temperature. The ZnO nano-seed layer was deposited on the glass substrate using a radio frequency sputtering discharge technique. The impact of three zinc salts with Hexamethylenetetramine (HMTA) on the properties of ZnO nanorods have been investigated. The double beam UV visible (UV4100) spectrometer, micro-Raman scattering, and Field emission scanning electron microscopy (FESEM) were used to characterize and study the optical properties, energy band gap, defects, Raman spectra, phase orientation, quality of material, the interaction of phonons, transport properties, and the morphology of synthesized ZnO nanorods (NRs), respectively. The three zinc salts are Zinc Nitrate Hexahydrate, Zinc Acetate, and Zinc Chloride. The results found that the variation in zinc salts types with Hexamethylenetetramine as deposition solution is play a very important impact on the structures of fabricated ZnO nanorods that effected directly on the optical properties, energy band, material quality, and phase orientation of ZnO NRs. Also, from UV measurement the optical properties and energy band gap of produced ZnO nanorods are changed with changing the zinc salt as a precursor of deposition solution.

Topological properties and direct current electrical charge transport mechanism of plasma polymerized cyclohexane thin films

High-performance plasma polymerized organic thin films have been synthesized by employing a capacitively coupled glow discharge technique and cyclohexane is used as a precursor material. The surface of the plasma polymerized cyclohexane (PPCHex) thin films observed to be smooth, pinhole free and uniform. It is observed from thermal analysis that the rate of loss of mass is very low in air atmosphere below 510 K and the films are thermally stable. Above 510 K weight loss takes place in different stages in air. The current density of the PPCHex thin films is increased when the thicknesses is decreased and that is increased with increasing temperatures. The conduction mechanism of carrier transport operative in these PPCHex thin film is dominated by Schottky type conduction mechanism. The activation energy of the PPCHex thin films for applied voltage 10 V is found 0.14 ± 0.05 eV near room temperature region and that in the higher temperature region is 0.57 ± 0.04 eV. The activation energy in the Schottky region for the applied voltage 50 V is about 0.16 ± 0.06 eV near the room temperature region and that is 0.83 ± 0.05 eV at the higher temperature region.

Hybrid DC-Bus Capacitor Discharge Strategy Using Internal Windings and External Bleeder for Surface-Mounted PMSM-Based EV Powertrains in Emergency

When electric vehicles (EVs) encounter an emergency, the voltage of the dc-bus capacitor in the surface-mounted permanent magnet synchronous motor (SPMSM)-based powertrain requires to be reduced as fast as possible. In order to eliminate the disadvantages and synthesize the advantages of the traditional machine-winding-based and external bleeder-based discharge techniques, this article proposes a hybrid discharge strategy that can achieve 5-s discharge in the minimum sacrifice of the bleeder size and weight for any EV drives. For the purpose of evaluating the size reduction of the new method, the individual bleeder-based scheme is modeled and analyzed at first. Then, the combined discharge method is developed, which contains two sequential procedures: bleeding resistor (BR) design and discharge control algorithm design. The BR design process has to be implemented under extreme condition. But concerning that the emergency might occur at the moment when the machine operates below the maximum speed, three different discharge modes including full-power, partial-power, and bleeder-based discharge modes are developed. The proposed discharge techniques are verified by experiments that are conducted on a three-phase SPMSM drive system used for EVs.

Manganese dioxide thin films deposited by chemical bath and successive ionic layer adsorption and reaction deposition methods and their supercapacitive performance

In present work, MnO2 thin films with tetragonal and birnessite-phases are deposited using chemical bath deposition (CBD) and successive ionic layer adsorption and reaction (SILAR) methods. The surface morphology of MnO2 film is modified using different deposition parameters. These films are characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, field- emission scanning electron microscopy (FE-SEM), Brunarer-Emmett-Teller (BET) and Barrette-Joynere-Halenda (BJH) method. The electrochemical properties are studied using cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy techniques in 1 M Na2SO4 electrolyte. The CBD method exhibits excellent electrochemical performance with maximum specific capacitance of 757F g−1 at scan rate 5 mV s−1, energy density of 74 Wh kg−1 at power density of 1.5 kW kg−1. The large area solid state symmetric devices fabricated with CBD MnO2 film electrodes exhibit maximum specific capacitance of 128F g−1 with energy density of 14 Wh kg−1 at power density of 0.2 kW kg−1 with capacitive retention of 90% after 5000 CV cycles. Such device is able to glow 211 red LEDs for the period of 160 s, showing it’s possible potential for commercialization.

Synthesis and characterization of mesoporous crystalline copper metal–organic frameworks for electrochemical energy storage application

The mesoporous nanostructure Cu-metal organic frameworks (Cu-MOF-1 and Cu-MOF-2) have been synthesized by a high temperature solvothermal route. The products were characterized by X-ray diffraction, Brunauer–Emmett–Teller surface measurement, Thermo gravimetric analysis, scanning electron microscope and Single crystal XRD. The electrochemical properties of these MOF electrodes were examined by using of cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopic techniques. Comparing the results of CV and GCD studies, both those MOFs have shown significant charge storage capacity, while Cu-MOF-2 has showed a specific capacitance greater than Cu-MOF-1. The Cu-MOF-1 and Cu-MOF-2 electrodes showed a maximum specified capacity of 181 and 248 F g−1 respectively at a current density of 1 A g−1 and an extensive cyclic stability of up to 2000 cycles with capacity retention of ~ 90.1%. The electrochemical studies with Cu-MOF electrodes were conducted in 6 M KOH electrolytes. The excellent electrochemical properties of Cu-MOFs can be credited to the large surface area with a high microporous volume of structurally implanted electro-active metallic centres and the rapid transport of ions into electrolytes/electrodes. The results imply that the Cu-MOFs electrode could be the potentially high- performance electrode materials for super capacitor applications.

Flexible and transparent capacitors based on gel‐type natural polymers

AbstractIn this work, we study the capacitive properties of gel‐type natural abundant polymers without any dopants, mainly commercial gelatin and agar in deionized water. Here, we propose a facile fabrication of flexible, transparent, and planar electrolytic capacitors using these gel‐type and indium tin oxide thin films as electrodes deposited on poly(ethylene terephthalate) substrates. Through cyclic voltammetry and galvanostatic charge–discharge techniques, we found that the devices show a specific capacitance in the order of the millifarads per gram, a specific power of ~10 mW cm−2, which is sufficient to active low‐power devices, and a life cycle with nearly 100% efficiency after 1,000 cycles. We found that we do not need to add dopants that improve the ionic conductivity of the natural polyelectrolytes to obtain capacitances within the millifarads per gram. The flexibility of the capacitors was demonstrated by bending them, after which they exhibited the same electrochemical performance as the unbent devices. The optical transparency of the capacitors was measured by UV–V is spectroscopy showing a high transmittance in the visible region.

Power Saving Electrochemical Processing of Low Cost MnO2@Porous Al Electrode for High Performance Supercapacitors Applications

The supercapactive properties for MnO2 coated on porous aluminum foil Al electrodes etched using various acidic baths and ethylene glycol (EG) as additive was studied. The optimum current densities for achieving high porous surface of Al foils using galvanostatic technique are 70 and 90 mA/cm2 in case of etching from acidic solution and when ethylene glycol is added respectively. Furthermore, cyclic voltammetry, galvanostatic charge–discharge techniques and electrochemical impedance spectroscopy were performed to determine specific capacitance and cycle life of the MnO2@ porous Al foil and MnO2@porous Al-EG electrode using 0.5 M Na2SO4 as electrolyte. The cyclic voltammteric curves for the two electrodes reveal that psuedocapacitive behavior during oxidartion – reduction reaction with maximum specific capacity 221.5 F/g at scan rate 20 mV/s for MnO2@ porous Al electrode. Moreover, the galvanostatic charge–discharge tests for MnO2@porous Al electrode at current densities 0.5 and 1 A/g show good pseudocapacitive performance and cycle ability with nearly linear curves forming quite triangle shape. Also, The EIS curves for both electrodes elucidate that, the total impedance of MnO2@porous Al cell is smaller than that of MnO2@porous Al-EG cell, so, MnO2@porous Al electrode has a high ionic conductivity between active material and ionic species. In addition to, both electrodes posse’s quite similar capacitive retention about 75% after 1000 cycles and this reveals the good adhesion and less dissolution of MnO2 film.

Synthesis and Characterization of NiFeCo3O4 Ternary Thin Film Electrodes for Supercapacitors Applications by Galvanostatic Method

At this present task, an attempt done in order to synthesize NiFeCo3O4 ternary thin film electrode by Electrodeposition method. Microstructure of the films studied using X-ray diffraction, energy dispersive X-ray spectroscopy (EDAX) and Field emission (FESEM) scanning electron microscopy. Films Electrochemical property were studied and confirmed with the help of charge discharge techniques using cyclic voltammetry, which confirms that the prepared electrode has excellent electrochemical capacitive behaviour with 757 F g–1 specific capacitance value of at the density in current about 1 mA g–1.

Inhibition of acid corrosion of glass ampoule in Pb/HBF4/PbO2 reserve batteries using nanobis[3-(trimethoxysilyl)propyl]amine

Corrosion inhibition properties of nanobis[3-(trimethoxysilyl)propyl]amine on corrosion of borosilicate 7740 Pyrex glass in a solution of synthesized HBF4 was analyzed through gravimetric, galvanostatic discharge, polarization Tafel, and EIS techniques. The results revealed that the degree of inhibitory effect rose with concentration. Further, kinetic and thermodynamic effects of temperature on corrosion rate were studied. Polarization and adsorption isotherm studies revealed that nanobis[3-(trimethoxysilyl)propyl]amine is a good anodic-type inhibitor. It was found that the adsorption isotherm can be described by the Langmuir model. Furthermore, microscopic surface analyses such as AFM, SEM, and EDX were used to characterize the surface morphology of borosilicate glass specimens.

Effect of annealing temperature on charge storage kinetics of an electrospun deposited manganese oxide supercapacitor

Nanofibers (NFs) Mn2O3 thin films are prepared by facial and cost effective single-nozzle electrospinning method. The effect of annealing temperature on structural, morphological and surface analysis of NFs coated thin films are investigated. XRD measurement reveals, the formation of cubic crystalline Mn2O3 above 400 °C annealing temperature. Vibration bonds at 515 and 624 cm−1 confirms the presence of Mn2O3 from Fourier transform infrared spectroscopy studies. Field emission scanning electron spectroscopy analysis shows the NFs like morphology of Mn2O3 are observed after heat treatment. The synthesized NFs have high specific surface area with pore size, which is beneficial for charge storage application. Electrochemical performance of electrospunn Mn2O3 NFs are evaluated by using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques. The sample annealed at 300 °C shows maximum specific capacitance of 526 F g−1 at 0.5 mA cm−2 in 1 M aq. Na2SO4 electrolyte. In addition, the NFs sample shows 96% retention in specific capacitance measured up to 1000 CV cycles. The storage of charge due to diffusion and capacitive controlled process are analysed in detail with their percentage contribution. It confirms that, the amorphous Mn2O3 NFs structure have high specific surface area and excellent capacitive performance as compared to crystalline Mn2O3.

Synthesis, characterization and electrical insulation of polyester plasma sprayed by (CaO3Si/CuO) nanoparticles

Textile fabrics possess multitude applications and a wide variety of highly technical uses. Microfiber is one of the most popular synthetic fibers. Its popularity is a result of special properties such as good resiliency, heat resistance, light weight, water proof and durability. In the present work, two woven fabrics were synthesized from polyester microfiber and then coated by calcium silicate/copper oxide-nanoparticles, (CaO3Si/CuO)-NPs, using low temperature plasma (dielectric barrier discharge) technique. The coated textiles were investigated by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX). A broadband dielectric spectroscopy (BDS) was employed to study the treatment conditions on the electrical and dielectric properties over a wide range of frequencies. The results showed that, the resistivity of the textile samples was remarkably enhanced upon coating with the (CaO3Si/CuO)-NPs) accompanied by a reduction of the static charges accumulated on the surface. These results made the plasma sprayed coated textiles promising for electrical applications like cables isolation as well as packing and packaging.

One pot and large-scale synthesis of nanostructured metal sulfides: Synergistic effect on supercapacitor performance

Metal sulfides received key interest as an electrode material for storage and conversion of energy. Here, the novel nanostructured N17S18 and (CoNi)3S4 materials were synthesized via one-step hydrothermal method, and the synergistic effect of metal ions and electrochemical properties was investigated. A new and simple solution growth technique was employed in this work. The prepared nanopowders were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy techniques. The X-ray diffraction analysis of the prepared nanopowder revealed the formation of cubic phase cobalt nickel sulfides (CoNi)3S4 and hexagonal phase nickel sulfides (Ni17S18). Scanning electron microscopy analysis display fibrous, flakes and sheet-like morphology for CoxSx, N17S18 and (CoNi)3S4, respectively. Fibrous and sheet-like morphology exhibits higher electrochemical performance in supercapacitors. The electrochemical behavior of the amorphous CoxSx, crystallite Ni17S18 and (CoNi)3S4 modified electrodes was investigated using electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge techniques. The specific capacitance of 57 F/g and 31 F/g were obtained for the amorphous CoxSx and crystalline (CoNi)3S4 powder, respectively. Amorphous CoxSx modified electrode retains 76% of initial capacitance after 1000 repeated cycling process. These results of this study suggest that the CoxSx and crystalline (CoNi)3S4 are appropriate materials for supercapacitor applications.

Нитрид алюминия, легированный переходными металлами, в качестве материала для спинтроники

Aluminum nitride doped with transition metal group atoms as a material for spintronics The overview of scientific literature on electric and magnetic properties of AlN doped with transition metal group atoms is presented. The review is based on literature sources published mainly in the last 10 years. The doping was carried out by different methods: during the material growth (molecular beam epitaxy, magnetron sputtering, discharge techniques) or by implantation into the material. The presented theoretical and experimental data show that AlN doped with transition metal group atoms has ferromagnetic properties at temperatures above room temperature and it is a promising material for spintronics.

Two new Zn (II) bdc Metal-Organic Frameworks based on benzene 1, 4-dicarboxylic acid: Synthesis, Crystal structures, Luminescent properties and Electrochemical studies

Abstract Two new one-dimensional (1D) Zinc Metal organic frame works, [Zn (BDC) (DMF) RT] (or Zn-MOF-1) and [Zn (BDC) (DMF) MW] (or Zn-MOF-2), where H2BDC = Benzene 1, 4 di-carboxylic acid, DMF = N, N-dimethylformamide, RT= Room temperature, MW= Microwave, have been synthesized through Room temperature and Microwave methods respectively. Zn-MOF-1; Zn-MOF-2 material was characterized by FTIR, Powder XRD, FE-SEM, Photo-luminescent, TGA and SXRD measurement. The electrochemical properties of these MOF electrodes were examined by using of Cyclic Voltammetry (CV), Galvanostatic Charge- Discharge (GCD) and Electrochemical Impedance Spectroscopic (EIS) techniques. Crystallographic studies show that the Zn-MOF-1 molecule has a one dimensional network in which the θ ranges from 6.86 to 54.92 with monoclinic P21/c space group, with Volume = 1015.9(4) A. In Zn-MOF-2 molecule θ ranges from 6.72 to 54.94 with monoclinic C2/c space group with Volume = 1265.9(3) A respectively. In comparison with Zn-MOF-1 and Zn-MOF-2 based on BDC derivatives both MOFs show strong luminescence along with red-shift, which indicates that these are the potential candidates for various luminescent applications

Electrochemical analysis of CuO-AC based nanocomposite for supercapacitor electrode application

In the present work, the activated charcoal-dispersed with Copper Oxide (CuO) nanoparticles (NPs) electrode materials has been proposed as electrode materials for supercapacitor that is used as energy storage device. The CuO NPs have been synthesized using co-precipitation method and the nanocomposite has been with activated charcoal (AC) powder for its application in an electrochemical supercapacitor. CuO nanoparticles calcination has been carried out at three different temperatures (400, 500, and 600 °C). The optimized temperature for synthesis is 600 °C that resulted into better performance of electrode materials. The Synchrotron X-ray diffraction (SXRD) confirms the monoclinic structure with space group C2/c (15). Electrochemical properties of the prepared nanocomposite electrodes and fabricated supercapacitor cells have been characterized using a.c. impedance, cyclic voltammetry (CV) and charge discharge (CD) techniques by using 6 M KOH as an the electrolyte. The optimized composition is 1:1 (mass ratio) of CuO and activated charcoal. The specific capacitance of the supercapacitor cell is stable up to 2000 cycles at 100 mV cm−2, which show that the device has good electrochemical reversibility and cycle life with 6 M KOH electrolyte.

Fabrication of supercapacitor using banyan leaves-based activated carbon electrode and formic acid-based polymer electrolyte

In the present studies, activated carbon as an electrode material and polyvinyl- alcohol (PVA) as a polymer. Formic acid (FA) and potassium iodide-based electrolyte system have been synthesized for the fabrication of energy storage devices, supercapacitors. The diluted formic acid (CH2O2) in the double-distilled (DD) water has been optimized so that it exhibits maximum conductivity. The electrolyte system has also been prepared with PVA, redox additive (KI) with optimized formic acid (4.0 M). The redox additive concentration has also been identified that can have maximum conductivity. The selected system (PVA + FA + KI) shows the highest conductivity in the range ∼10−1 Scm−1. The banyan leaves (biomass) based carbon electrode (BAC) synthesized as an electrode material. The electric double layer capacitor (EDLC) has been fabricated using BAC as electrodes and (PVA + FA + KI) as electrolyte material. The result of (BAC) based EDLC cell has been compared with the cell fabricated using commercially available activated carbon (AC). The performance of cells has been determined by impedance spectroscopy (IS), Cyclic voltammetry (CV) and charge–discharge (CD) techniques. The overall capacitance of BAC / (PVA + FA + KI) / BAC and AC / FA (4.0 M) / AC have been found to be ∼356 mFcm−2 and ∼100 mFcm−2.