Wire Explosion Process Research Articles

Synthesis of nano-ZnO by wire explosion process and its photocatalytic activity

Zinc oxide (ZnO) nanoparticles were produced by wire explosion process and characterized through X-ray diffraction (XRD) studies and by TEM studies. The particle size analysis indicates that they follow log-normal distribution and the mean size of the ZnO nanoparticles formed is about 44nm. Optical band gap of ZnO is found to be 3.21eV by UV–vis diffuse reflectance spectroscopy (DRS). The synthesized ZnO nano particles were used as photo catalyst for degradation of methylene blue (MB) in aqueous solution. Nano zinc oxide of 100mg/L was found as the optimum quantity for UV photo degradation of 10mg/L MB. ZnO nanoparticles were verified for its reusability. The results of the study are compared with commercial ZnO nanoparticle and with Degussa P-25 TiO2. LC-MS studies were carried out to identify the intermediates and degradation pathway.

Thermodynamic analysis of ZnO nanoparticle formation by wire explosion process and characterization

Zinc Oxide (ZnO) nanoparticles were synthesized by wire explosion process through deposition of different levels of energy to the exploding conductor in oxygen ambience at different pressures. The produced nanoparticles were analyzed by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive analysis of X-rays (EDAX) and by Brunauer-Emmett-Teller (BET) studies. Energy dependent formation reaction mechanisms were formulated based on Born-Haber cycle. The size dependent gas phase reaction energetics was analyzed by using Hess's diagram. Butler's multicomponent molten oxide model was adopted to predict the surface tension of ZnO. Thermodynamic modelling studies revealed that the amount of energy deposited has an impact on saturation ratio, activation free energy, and nucleation rate of nanoparticles. It is observed based on experimental and modelling studies that the amount of energy deposited to the current carrying conductor, ambient pressure of oxygen and the saturation ratio influence the size of nanoparticle formed.

Thermodynamic modeling and characterizations of Al nanoparticles produced by electrical wire explosion process – CORRIGENDUM

Thermodynamic modeling and characterizations of Al nanoparticles produced by electrical wire explosion process – CORRIGENDUM

Thermodynamic modeling and characterizations of Al nanoparticles produced by electrical wire explosion process

Abstract

Characterization of Magnesium Oxide Nanosheets Prepared by Electrical Wire Explosion Process

Characterization of Magnesium Oxide Nanosheets Prepared by Electrical Wire Explosion Process

Rapid fabrication and characterization of spherical Mumetal nanoparticles by an electrical wire explosion process

abstractSpherical Mumetal nanoparticles fabricated by the electrical wire explosion process in 1% solution of poly(acrylamide-co-acrylic acid) partial sodium salt as the explosion medium and capping agent to prevent particle agglomeration and control the size of nanoparticles. The structure, morphological features were studied by field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDX) and Transmission Electron Microscope (TEM). The size distribution and the principle elements analysis of Mumetal nanoparticles were analyzed. The DC magnetic properties of Mumetal nanoparticles were carried out on a Quantum Design superconducting quantum interference device (SQUID) and the temperature-dependence of mass magnetic susceptibility χ (T) and its inverse 1/χ for the Mumetal nanoparticles were measured in field-cooling (FC) procedures in an applied magnetic field of 50000 Oe between 2 and 300 K.

Electrical wire explosion process of copper/silver hybrid nano-particle ink and its sintering via flash white light to achieve high electrical conductivity

In this work, combined silver/copper nanoparticles were fabricated by the electrical explosion of a metal wire. In this method, a high electrical current passes through the metal wire with a high voltage. Consequently, the metal wire evaporates and metal nanoparticles are formed. The diameters of the silver and copper nanoparticles were controlled by changing the voltage conditions. The fabricated silver and copper nano-inks were printed on a flexible polyimide (PI) substrate and sintered at room temperature via a flash light process, using a xenon lamp and varying the light energy. The microstructures of the sintered silver and copper films were observed using a scanning electron microscope (SEM) and a transmission electron microscope (TEM). To investigate the crystal phases of the flash-light-sintered silver and copper films, x-ray diffraction (XRD) was performed. The absorption wavelengths of the silver and copper nano-inks were measured using ultraviolet–visible spectroscopy (UV–vis). Furthermore, the resistivity of the sintered silver and copper films was measured using the four-point probe method and an alpha step. As a result, the fabricated Cu/Ag film shows a high electrical conductivity (4.06 μΩcm), which is comparable to the resistivity of bulk copper (1.68 μΩcm). In addition, the fabricated Cu/Ag nanoparticle film shows superior oxidation stability compared to the Cu nanoparticle film.

Effect of Liquid Media on the Formation of Multi-Layer Graphene-Synthesized Metal Particles.

We report a simple approach for the production of copper nanoparticles by a wire explosion process that creates different structures in deionized (DI) water versus isopropyl alcohol (IPA) liquid media. In DI water, copper nanoparticles (CNs) are formed, while multi-layer graphene-synthesized copper nanoparticles (MGCNs) with a high degree of graphitization are formed in the IPA liquid media. The nanoparticles have an average diameter ranging from 10 nm to 300 nm and a quasi-spherical morphology. The morphologies and sizes of nanoparticles formed via this method were characterized by high-resolution transmission electron microscopy (HRTEM), field-emission scattering electron microscopy (FESEM), and analysis of dynamic light scattering (DLS). The microstructures and chemical bonding of the nanoparticles were studied by X-ray diffraction (XRD), Raman spectra measurement, and X-ray photoelectron spectroscopy (XPS). This results show an easily reproducible way to synthesize metal-core nanoparticles with multi-layer graphene shells based onto the liquid media used during synthesis. These materials can be used in the field of energy storage and as additives in the near future.

Investigation of Nano-Molybdenum Carbide Particle Produced by Wire-Explosion Process

Molybdenum carbide (MoC) nanoparticles were generated by exploding molybdenum conductor in methane gas ambience at different pressures. To enhance the level of carburization, exploding conductor was coated with graphite and paraffin mixtures. Various physico-chemical studies were employed to characterize the produced nano-carbide particles, viz., X-ray diffraction, optical emission spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. It was deduced from these investigations that the nano-MoC particles produced by a wire explosion process (WEP) are spherical in shape. The size of the particles formed by WEP can be controlled by varying the operating ambience pressure of the methane gas. The particle size produced follows a log-normal distribution. Optical emission results clearly indicates the presence of Mo-I, C-I, and C-II components during WEP. X-ray photoelectron spectroscopy confirms the formation of MoC.

Electrical Explosion Synthesis of Si/C Nanocomposites for Li Secondary Batteries

A novel technique of electrical explosion has been used for nanomaterial synthesis by a single-step process [1-5]. However, it was known that in principle the electrical explosion of Si is not possible due to the fact that applying a high voltage on Si wire having relatively high electrical resistance leads to a current flow through surface plasma formed along the wire which disables the resistive heating of Si. In this presentation, we will show the successful application of electrical explosion to silicon nanoparticle synthesis and the electrochemical properties of Si/C nanocomposites derived from the nanoparticles.The electrical explosion of Si was successfully applied using a liquid media to suppress the unfavorable surface plasma generation. The physical and chemical properties of the produced materials were analyzed by XRD, FE-SEM, HR-TEM and the performances of the Si/C composites as an anode for Li ion batteries were investigated by electrochemical charge/discharge measurements. The Si/C composites obtained under the explosion in hexane and ethanol consist of a core-shell structure with a compact graphitic carbon on the Si particle surface which cause detrimental effects against Li ion diffusion. However, we found that Si explosion in methanol minimized the formation of the carbon phase on the surface of nano-sized Si. The Si/C nanocomposite after a simple pyrolysis with carbon precursor showed a high capacity with an excellent cycle performance.[1] Cho, C., Choi, Y.W., Kang, C., Lee, G.W. Effects of the medium on synthesis of nanopowders by wire explosion process (2007) Applied Physics Letters, 91 (14), p. 141501.[2] Cho, C., Ha, Y.-C., Kang, C., Jin, Y.-S., Rim, G.-H. Preparation of a nickel nanopowder by wire explosion in liquid media (2010) Journal of the Korean Physical Society, 57 (61), pp. 1807-1810.[3] Ha, Y.-C., Cho, C. Production of highly-dispersed nano-sized Sn powders in a liquid medium by using a high-energy electrical explosion (2010) Journal of the Korean Physical Society, 57 (61), pp. 1574-1576.[4] Cho, C., Ha, Y.-C., Kang, C., Jin, Y.-S., Rim, G.-H. Electrical explosion of silicon rod in distilled water (2011) Japanese Journal of Applied Physics, 50 (10 PART 1).[5] Ha, Y.-C., Kang, C., Cho, C., Kim, Y.-U., Park, C.-M., Sohn, H.-J. Wire explosion synthesis of a Sn/C nanocomposite as an anode material for Li secondary batteries (2011) Journal of the Korean Physical Society, 59 (61), pp. 3458-3462.

Observation of the partial reheating of the metallic vapor during the wire explosion process for nanoparticle synthesis

In this paper, an experimental study using time resolved imaging was reported to study the expansion of the vapor as well as subsequent formation of the arc plasma during the synthesis of Cu nanoparticles by wire explosion process to understand the influences of arc plasma formation on the characteristics of the produced nanoparticles by means of partial reheating of the vapor. Arc plasma is known to form after a delay or immediately depending on the ambience and pressure when the supplied energy is sufficient to sustain the plasma. Observations of two expanding concentric cylinders one inside another by time resolved imaging in the case of delayed formation of arc plasma suggest that the vapor of the wire material is expanding in front of the expansion of the arc plasma. Due to the expansion of the vapor in front of the arc plasma, some of the wire material may not be reheated by arc plasma as opposed to the case of immediate formation of arc plasma, where the vapor is expected to be reheated completely. Thus, the arc plasma formation has strong influence on the characteristics of the produced nanoparticles in wire explosion process and most probably explains the earlier reported opposite trends observed for particle size with varying pressure for different gases.

Preparation of conductive metal patterns using Cu nano-colloids prepared by electrical wire explosion process

A simple patterning process to prepare conducting circuits in the atmosphere with the irradiation of laser and complex Cu nano-colloid was demonstrated. Stable Cu nano-colloids with a particle size of less than 10 nm were produced by an electrical wire explosion process in anhydrous ethanol. Uniform Cu film without cracks was prepared by using a Cu nano-colloid with copper(II) nitrate trihydrate. Various kinds of conductive Cu patterns on a flexible substrate were prepared by laser irradiation in air. The Cu pattern on a flexible polyimide substrate showed about 40 Ω/square of electrical sheet resistance.

정전 분무 공정으로 제조된 Fe-Cr-Al 분말 다공체 금속의 고온 산화 특성에 미치는 기공 크기의 영향

【Fe-Cr-Al powder porous metal was manufactured by using new electro-spray process. First, ultra-fine fecralloy powders were produced by using the submerged electric wire explosion process. Evenly distributed colloid (0.05~0.5% powders) was dispersed on Polyurethane foam through the electro-spray process. And then degreasing and sintering processes were conduced. In order to examine the effect of cell size ( $200{\mu}m$ , $450{\mu}m$ , $500{\mu}m$ ) in process, pre-samples were sintered for two hours at temperature of $1450^{\circ}C$ , in $H_2$ atmospheres. A 24-hour thermo gravimetric analysis test was conducted at $1000^{\circ}C$ in a 79% $N_2$ + 21% $O_2$ to investigate the high temperature oxidation behavior of powder porous metal. The results of the high temperature oxidation tests showed that oxidation resistance increased with increasing cell size. In the $200{\mu}m$ porous metal with a thinner strut and larger specific surface area, the depletion of the stabilizing elements such as Al and Cr occurred more quickly during the high-temperature oxidation compared with the 450, $500{\mu}m$ porous metals.】

Highly Reversible Li Storage in Hybrid NiO/Ni/Graphene Nanocomposites Prepared by an Electrical Wire Explosion Process

NiO/Ni/graphene nanocomposites were prepared using a simple and environmentally friendly method comprising an electrical wire pulse technique in oleic acid containing graphenes and subsequent annealing to form anodes for Li ion batteries. The control product of NiO/Ni nanocomposite was prepared under the same conditions and characterized by structural and electrochemical analysis. The obtained NiO/Ni/graphene nanocomposite particles had sizes of 5-12 nm and a high surface area of 137 m(2) g(-1). In comparison to NiO/Ni, NiO/Ni/graphene exhibited improved cycling performance and good rate capability. Reversible capacity was maintained at over 600 mA h g(-1) at 0.2 C and was attributed to the alleviation in volume change and improved electrical conductivity of NiO/Ni/graphene nanocomposites.

Preparation of Conductive Cu Thin Film by the Reaction of Cu Nitrate with Polymers

Cu nanoparticle-colloid was prepared by using electrical wire explosion process in liquid and it showed good dispersion stability without any kinds of additives. Mixed Cu nano-colloid was prepared with Cu nanoparticle-colloid, Copper (II) nitrate trihydrate, and polyvinyl pyrrolidone. Cu atoms are supplied from the dissociation reaction between Copper (II) nitrate trihydrate and polyvinyl pyrrolidone and fill up the gaps between Cu nanoparticles during the thermal sintering. Conductive (45 microOmega cm) Cu film was prepared at the sintering temperature of 200 degrees C by the enhancement of the formation of sintering necks.

Understanding the Mechanism of Nanoparticle Formation in a Wire Explosion Process by Adopting the Optical Emission Technique

In the present study nano-tungsten carbide particles were generated in a wire explosion process. The plasma generated during the wire explosion process was analyzed using optical emission spectroscopy (OES). The impact of ambient pressure on the plasma temperature, electron density and plasma lifetime was studied. Lifetime variations of the plasma produced under different experimental conditions were analyzed. The produced nanoparticles were characterized through wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM) studies. Particles produced with a negative DC charging voltage had a larger mean size when compared to a positive charging voltage. Polarity dependence on the plasma duration was observed where plasma was sustained for a longer duration with a negative DC charging voltage.

정전 분무법을 이용하여 제조된 Fe-Cr-Al 분말 다공체 금속의 고온 산화에 미치는 소결 온도의 영향

A new manufacturing process of Fe-Cr-Al powder porous metal was attempted. First, ultra-fine fecralloy powders were produced by using the submerged electric wire explosion process. Evenly distributed colloid (0.05~0.5% powders) was dispersed on PU (Polyurethane) foam through the electrospray process. And then degreasing and sintering processes were conduced. In order to examine the effect of sintering temperature in process, pre-samples were sintered for two hours at temperatures of <TEX>$1350^{\circ}C$</TEX>, <TEX>$1400^{\circ}C$</TEX>, <TEX>$1450^{\circ}C$</TEX>, and <TEX>$1500^{\circ}C$</TEX>, respectively, in <TEX>$H_2$</TEX> atmospheres. A 24-hour TGA (thermo gravimetric analysis) test was conducted at <TEX>$1000^{\circ}C$</TEX> in a 79% <TEX>$N_2$</TEX>+21% <TEX>$O_2$</TEX> to investigate the high temperature oxidation behavior of powder porous metal. The results of the high temperature oxidation tests showed that oxidation resistance increased with increasing sintering temperature (2.57% oxidation weight gain at <TEX>$1500^{\circ}C$</TEX> sintered specimen). The high temperature oxidation mechanism of newly manufactured Fe-Cr-Al powder porous metal was also discussed.

Understanding the mechanism of nanoparticle formation in wire explosion process

The mechanism of nanoparticle formation by wire explosion process has been investigated by optical emission spectroscopy in Antony et al. 2010 [2] [J Quant Spectrosc Radiat Transfer 2010; 111:2509]. It was reported that the size of the nanoparticles formed in Ar ambience increases with increasing pressure, while an opposite trend was observed for the nanoparticles produced in N2 and He ambiences. However, the physics behind this opposite trend seems unclear. In this work, we have investigated the probable mechanism behind the opposite trend in particle size with pressure of different gases and understand the mechanism of nanoparticle formation in wire explosion process. The experiment was carried out to investigate the effect of ambient gas species (Ar and N2) and pressure on arc plasma formation and its corresponding effects on the characteristics of the produced nanoparticles in wire explosion process. Our results show that the arc plasma formation is probably the mechanism that may account for the opposite trend of particle size with pressure of different gases.

Impact of binary gas on nanoparticle formation in wire explosion process: An understanding via arc plasma formation

Recently, impact of binary gas on nanoparticle formation through wire explosion process has been investigated [Materials Letters 2007; 61:1823–1826]. However, the experimental observations seemed to be inconsistent with the explanations. In this work, effect of the ambient gas species on the characteristics of the produced nanoparticles in wire explosion process is investigated to understand the inconsistent experimental observations. Cu wire was exploded in ambiances of Ar, N2 and their admixtures with different ratios. X‐ray diffraction and transmission electron microscopy are used to characterize the as synthesized nanoparticles. Considerable variation in arc plasma formation time and their impact on the characteristics of the produced nanoparticles with ambient gas species are observed. Arc plasma formation is found to be a probable reason for the inconsistent experimental observations with the explanations.

Effect of ambient gas species on the formation of Cu nanoparticles in wire explosion process

In this paper, the effect of ambient gas species on the characteristics of the produced nanoparticles in wire explosion process is reported. Cu wires with a diameter of 125 μm and length of 6.1 cm were exploded in different ambiances of Ar and admixtures of Ar and N2 at 500 mbar pressure. Immediate formation of arc plasma is observed for Ar ambiance. On the other hand, considerable delay in formation of arc plasma is observed for the admixtures of Ar and N2. The arc plasma formation time is found to increase with increasing N2 concentration in the admixture. Transmission electron microscope and X-ray diffraction were used to characterize the produced nanoparticles. Among the nanoparticles produced in different ambient gas species, the nanoparticles produced in Ar ambiance have higher particle size compared to admixtures of Ar and N2. The particle size is found to reduce with increasing N2 concentration in the ambiance. Difference in arc plasma formation time is probably the factor that gives rise to the difference in the particle sizes.