Conductive Powder Research Articles

Preparation and Properties of Y and Sb Doped SnO<sub>2</sub> Conductive Powders

Y is used as a dopant for the first time in preparing conductive powders to improve its performance. Y and Sb doped SnO2 conductive particles are prepared by the complexation-coprecipi-tation method with Sn, Sb2O3 and Y2O3 as the raw materials. The crystal phase and structure of the prepared conductive particles are characterized by FTIR and XRD techniques respectively. The resistivity of the prepared conductive powders are measured with four-point measurement method. The resistivity of Y and Sb doped SnO2 conductive particles is 0.22 Ωcm. FTIR spectrum of Y and Sb doped SnO2 conductive particles shows that the vibration peak are wide peak in 570 cm-1 ~ 400 cm-1, and have intense absorption in 4000 cm-1 ~ 2500 cm-1, respectively.Y and Sb doped SnO2 conductive powders have a structure of tetragonal rutile. The complex doping is achieved well by complexation-coprecipitation method and is recognized as replacement doping or caulking doping.

Conductive glass sealants with Ag nanoparticles prepared by a heat reduction process

Conductive Ag-precipitated glass powder was prepared by a heat reduction process of the glass/AgCl composite powder and its electrical conductivity was compared to conventional Ag-particle mixed glass powder. The Ag-precipitated glass powder with 30wt.% dispersed Ag particles of diameter of 20 to 300nm and the baked film made of the powder showed a good electrical conduction from 400°C to 700°C. On the other hand, the baked films made of the Ag-particle mixed glass powders of Ag particle size of 300nm with 35wt.% Ag content and that of size of 20nm with 30wt.% Ag content showed a poor electrical conduction. The electrical conduction of the film of Ag-precipitated glass powder resulted from a uniform dispersion of Ag particles. Since no continuous network of Ag particles was found in the microstructure observation of the glass powders, or films, the origin of the electrical conduction was considered to be due to a tunneling effect between the well-dispersed Ag particles.

High electrical conductivity in Ni₃(2,3,6,7,10,11-hexaiminotriphenylene)₂, a semiconducting metal-organic graphene analogue.

Reaction of 2,3,6,7,10,11-hexaaminotriphenylene with Ni(2+) in aqueous NH3 solution under aerobic conditions produces Ni3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene), a new two-dimensional metal-organic framework (MOF). The new material can be isolated as a highly conductive black powder or dark blue-violet films. Two-probe and van der Pauw electrical measurements reveal bulk (pellet) and surface (film) conductivity values of 2 and 40 S·cm(-1), respectively, both records for MOFs and among the best for any coordination polymer.

Energy-Saving Sintering of Electrically Conductive Powders by Modified Pulsed Electric Current Heating Using an Electrically Nonconductive Die

Sintering of Cu and thermoelectric Ca3Co4O9 was tried using a modified pulsed electric current sintering (PECS) process, where an electrically nonconductive die was used instead of a conventional graphite die. The pulsed electric current flowed through graphite punches and sample powder, which caused the Joule heating of the powder compact itself, resulting in sintering under smaller power consumption. Especially for the Ca3Co4O9 powder, densification during sintering was also accelerated by this modified PECS process.

Optimization of Parameters Using Conductive Powder in Dielectric for EDM of Super Co 605 with Multiple Quality Characteristics

Experiments were performed using conductive powder-mixed dielectric in electrical discharge machining of Super Co 605 and optimization is carried out by means of Taguchi method. The process input parameters selected are flushing pressure, discharge voltage, pulse on-time, polarity, peak current, and pulse off-time to study the performance characteristics in the form of surface roughness, tool wear, and material removal rate. Experiments based on appropriate orthogonal array are conducted and significant parameters are identified. The optimum process conditions simultaneously leading to a better surface roughness, lower tool wear, and higher material removal rate are then demonstrated by confirmation testing. The experimental results confirm an improvement in surface roughness, tool wear, and material removal rate when Taguchi method is used.

Homogeneous dispersion of high-conductive reduced graphene oxide sheets for polymethylmethacrylate nanocomposites

The high cohesive interaction between reduced graphene oxide (RGO) sheets usually makes them difficult to disperse, which limits their utilization in achieving effective hybridization with polymers. We report here a new two-step route for preparing non-aggregated and high-conductive RGO powders. Graphene oxide precursor was first reduced by hydrazine hydrate in presence of a thermal unstable surfactant of cetyltrimethylammonium chloride (CTAC). Then a thermal annealing process under H2/Ar atmosphere was further used to remove the non-conductive CTAC molecules. The prepared RGO powder exhibited an electrical conductivity of 2.23 × 104 S m−1 – about ten times higher than the one (N-RGO) simply reduced by hydrazine hydrate. After incorporating into polymethylmethacrylate with a 5 wt% loading, the composite showed a conductivity of 4.11 S m−1, which was 60 times as high as that of the same composite based on N-RGO powder. The addition and subsequent removal of CTAC molecules is an effective method for preparing non-aggregated and highly conductive graphene powder and obtaining good incorporation into polymer matrices.

On the electrical conductivity and photocatalytic activity of aluminum-doped zinc oxide

Aluminum-doped zinc oxide (AZO) conductive powders have been successfully prepared by a simple chemical coprecipitation method. The obtained powders with different post-calcining atmospheres were characterized using X-ray powder diffraction (XRD), scanning electron microscopy (SEM/EDS), and dynamic light scattering (DLS). The resistivity-dependent photocatalytic activity was studied by degradation of methyl orange (MO) in aqueous solution. The result showed that photodegradation of methyl orange dyes obeyed the rule of a pseudo first-order kinetics reaction and the AZO photocatalytic activity was related to the resistivity under different post-calcining atmospheres.

Piezochromic Phenomena of Nanometer Voids Formed by Mono-Dispersed Nanometer Powders Compacting Process

Piezochromism describes a tendency of certain materials changing colors when they are subjected to various pressure levels. It occurs particularly in some polymers or inorganic materials, such as in palladium complexes. However, piezochromism is generally believed to work at high pressure range of 0.1–10 GPa. This research work focused on unique piezochromism responses of the nanometer voids formed by the 5–20 nm inorganic ISOH nanometer powders. It was discovered that microstructures of the nanometer voids could change color at very low pressures of only 0.002–0.01 GPa; its sensitivity to pressure was increased by tens of times. It is believed that the uniform microstructures of nanometer powders contributed to the material's high sensitivity of piezochromic phenomena. One factor which quantum optical change caused by nanometer voids affected the quantum confinement effect; another is surface Plasmon Resonance of great difference dielectric property between conductive ITO powder and insulation hydroxide.

Polypropylene filled with kaolinite-based conductive powders

Antimony doped tin oxide nanoparticles (Sb–SnO2) were uniformly coated on the surfaces of rod-/flake-like kaolinites (Kaol) to synthesize kaolinite-based conductive powders (Sb–SnO2)Kaol, which was then added into polypropylene (PP) matrix to produce conductive (Sb–SnO2)Kaol–PP nanocomposites. The effects of (Sb–SnO2)Kaol characteristics on the volume resistivity and mechanical properties of (Sb–SnO2)Kaol–PP were in detail investigated. The results indicated that surface-modified (Sb–SnO2)Kaol could improve the dispersion in PP matrix, and the as-synthesized nanocomposites showed better electrical property than that without surface modification. The volume resistivity of (Sb–SnO2)Kaol–PP reached 7.3×108Ω·cm at the (Sb–SnO2)Kaol concentration of 40%, 6–7 order of magnitude lower than that of pure PP. The as-synthesized (Sb–SnO2)Kaol–PP nanocomposites could show potential applications in the conductive fields.

Synthesis and characterization of conductive composite films of polyisoprene/PA12@ PANI

ABSTRACTPolyamide@Polyaniline powders of core‐shell structure are known to have reduced conduction thresholds useful to maintain the mechanical and optical properties of the matrix. However, difficulties emerge at the synthesis stage, where dissolving the matrix without damaging the core‐shell particles becomes a challenge. The present solution avoids using solvents. Conductive polymer films containing solid Polyamide@Polyaniline particles are elaborated by UV photoreticulation of a liquid polyisoprene serving as a matrix. The conductive powders are obtained by in‐situ polymerization of aniline in presence of polyamide 12 (PA12) at room temperature using Dodecyl benzene sulfonic doping acid and Ammonium persulfate oxidant. Obtained films exhibit low percolation threshold compared to those containing pure solid polyaniline (PANI) particles even more conductive. This threshold is shown to be about 1.5 wt % of PANI. Films show good electrical conductivity and thermal stability up to 200°C allowing their use as antistatic polymer films for high temperatures. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39833.

Feasibility of electrochemical chloride extraction from structural reinforced concrete using a sprayed conductive graphite powder–cement paste as anode

Abstract This article summarizes research on the application of a conductive cement paste as an anode in the now classical technique of electrochemical extraction of chlorides applied to a concrete structural element by spraying the paste on the surface of a concrete structural element, a pillar. Sprayed conductive cement paste, by adding graphite powder, is particularly useful to treat sizable vertical surfaces such are structural supports. Outcomes indicate that this kind of anode not only provides electrochemical chloride removal with similar efficiency, but also is able to retain moisture even without the use of a continuous dampening system.

도전성 분말에 의한 아크전류의 파형 및 실효값 특성

도전성 분말에 의한 아크전류의 파형 및 실효값 특성

Studying on Hot Pressure Casting Process of CaZr<sub>0.9</sub>In<sub>0.1</sub>O<sub>3-α</sub> Tubes for Hydrogen Sensor in Aluminum Melt

The relationship of the powders and binder system and forming process on the quality of the U-shaped proton conducting CaZr0.9In0.1O3-α tubes was studied. The results showed that defect-free green bodies can be obtained under the conditions of the wax slurry containing 87.8% (mass percentage, the same below) proton conductor powders, 11% paraffin wax, 1% beeswax and 0.2% oleic acid, the wax slurry and mold temperature at 73°C and 30°C, the casting pressure and time at 0.5MPa and 15s. A reasonable wax removing schedule about the green bodies was put forward. At last the sintered samples were characterized by higher density and less shrink rate and distortion.

Observation on Non-Conductive Powder Samples by Scanning Electron Microscope

Different fixation methods have significant influence on observation of samples by scanning electron microscopy when non conductive samples are processed by plasma spudtter coating method. Non conductive powder samples using different treatments are observed on Philips XL30 scanning electron microscope and Hitachi S-4800 field emission scanning electron microscope. For the small size samples processed by two fixation methods, Sample shape were observed more clearly by the ultrasonic dispersion preparation on scanning electron microscope and had less interference of ion sputtering thermal effect. The effect is not obvious for the large size samples, and the effect of observation for non conducting samples is better on field emission scanning electron microscope at low accelerating voltage.

Nickel ethylene tetrathiolate polymers as nanoparticles: a new synthesis for future applications?

Coordination polymers (CP) based on the ethylene tetrathiolate ligand (C2S4)4− and Ni2+, and previously isolated as insoluble conductive powders are grown as nanoparticles (NP) using ionic liquid (IL) as stabilizing agent. The time of addition of the IL determines the morphology, and consequently the properties of the CP. The smaller (10–20 nm) and soluble NP are obtained when IL is present at the complexation step. The mechanism of growth of NP is studied. The NP size is sensitive to the amount of IL and to the reaction temperature. NPs are studied by TEM/EDX, DLS, liquid- and solid-state NMR, and conductivity.

Study on Multilayer Electromagnetic Shielding Coating Fabrics Based on Graphite and Nickel

Nickel and graphite are selected as conductive powders. Water-based adhesive are selected as coating. Electromagnetic shielding textiles were prepared with coating method. In order to improve the shielding effectiveness of textiles, multilayer compositing is used. The surface resistivity, coating amount, electromagnetic shielding effectiveness are tested to select the best process.

High Capacity and Rate Capability of Amorphous Phosphorus for Sodium Ion Batteries

Turning on your P/C: An amorphous phosphorus/carbon (a-P/C) composite was synthesized using simple mechanical ball milling of red phosphorus and conductive carbon powders. This material gave an extraordinarily high sodium ion storage capacity of 1764 mA h g(-1) (see graph) with a very high rate capability, showing great promise as a high capacity and high rate anode material for sodium ion batteries.

Study on Preparation of Electromagnetic Shielding Coating Based on Nickel/PET

In this paper we select nickel as conductive powders, water-based adhesive as coating, PET as fabrics, electromagnetic shielding textiles were prepared by coating method. PET fabrics treated with sodium hydroxide before coating at the best concentration of 3%. Between the condition of 30MHz and 1500MHz, the SE of nickel/PET electromagnetic shielding coating can stable at about 37.0dB.It meets the requirement of environmental protection, and has widespread application foreground.

Flaky silver powders prepared with nanofilm transition method: application for printable electronics

A novel nanofilm transition method is put forward to prepare highly conductive flaky silver powders. The superior electrical properties of the flaky silver powders used in printable electronics are experimentally demonstrated. The resulting silver flakes exhibit a rather low bulk resistivity of 4.6 × 10−4 Ω cm at 20 wt% of flaky silver powders.

Model of heating and ignition of conductive polydisperse powder in electrostatic discharge

Heating of a conductive polydisperse powder by electrostatic discharge (ESD) is modelled numerically. Powder packing is described using a discrete element model; powder resistance is defined by geometry of particle contacts and properties of plasma produced by electrical breakdown between neighbour particles. A set of parametric calculations in combination with experimental data is used to determine necessary adjustable model parameters. The model predicts the temperature for each powder particle resulting from its heating by the ESD current. Location and packing of individual particles within the powder affects greatly their achieved temperatures and thus the likelihood of ignition. Consistently with experiments, a trend showing that smaller particles are generally heated to higher temperatures at a given ESD energy is detected for coarser powders; this trend becomes less clear for finer powders with particle sizes less than the breakdown distance given by the Paschen curve in air. Comparison of the experimental data and calculations suggests that the transition from single particle to cloud combustion occurs when the distance between the particles ignited by ESD becomes close to the flame size for the individual burning particle. This distance, inversely proportional to the number of ignited particles, is primarily determined by the ESD energy.