The preparation of ultrafine silver powder with chemical reduction method was investigated. Ascorbic acid was employed as reducing agent. Reaction of AgNO 3 with ascorbic acid gives polyhedron monodispersed ultrafine silver powder. Effect of reaction temperature on particles was studied.
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Preparation of ultrafine nickel powder and its catalytic dehydrogenation activity [J]. Materials Chemistry and Physics, 2001, 71(2): 215-219. [7] YOSHINAGA H, ARAMI Y, KAJITA O, SAKAI T. Highly densed-MH electrode using flaky nickel powder and gas-atomized hydrogen storage alloy powder [J]. Journal of Alloys and Compounds, …
We propose a process to produce ultrafine W-10 wt pct Cu composite powders by reducing the mixtures of copper tungstate (CuWO4) and tungsten trioxide (WO3) (from the calcination of a mixture of ammonium paratungstate and copper nitrate trihydrate) with carbon black and hydrogen. First, ultrafine pre-reduced tungsten-copper …
Abstract. Sol-gel method was employed for the preparation of nanoscale tungsten powder. The effects of different preparation conditions on particle size were discussed and the optimum preparation ...
The purpose of this study was to prepare ultrafine beclomethasone dipropionate (BDP) powder via antisolvent precipitation without any surfactants. Various solvents were screened to determine the suitable system for optimum processing while deionized water was kept as the antisolvent. Methanol was selected as the solvent, …
The powder could be utilized as adsorbent or the carrier of catalyst. Further, cyclohexane/Triton X-100/pentanol/water was taken by Tang et al. [12] as the microemulsion. Ultrafine spindle zirconia powder of monoclinic with the diameter of 4–20 nm was prepared while a relative low reactant concentration was employed.
Ultrafine copper powders were prepared by the air-jet milling of copper oxide (CuO) powders and a subsequent hydrogen (H 2) reduction. After milling, the particle …
The synthesis method of titanium nitride powder mainly includes carbothermal reduction method [[14], [15] ... Preparation of titanium nitride ultrafine powders by sol–gel and microwave carbothermal reduction nitridation methods. Ceram. Int., 35 (2009), pp. 1071-1075.
In this study, ultrafine borides powders including (W,Mo)B, (W,Mo)B 2.5 and (Mo,W)AlB were successfully fabricated via boronizing ultrafine W-Mo solid solution composite powder with B 4 C as the boron source under the assistance of Ca melt or Al melt. Ultrafine W-Mo solid solution powder was obtained by using a two-stage …
It is difficult to obtain ultrafine or nanoscale W powder for the traditional preparation technology. The main reason is that the water vapor generated during the hydrogen reduction process reacts with tungsten oxide to generate volatile WO 2 (OH) 2, which will be further reduced by hydrogen and deposited on the surface of tungsten …
Summary The preparation of ultrafine powder involves many unit processes, and the significant economic and aca- demic value will prompt scientists to do further studies in this new field. All these processes have provided a new chance, as well as a challenge, for chemical engi- neering. Table 1 summarizes, in detail, the main engi- …
A more dispersed ultrafine/nano-MoO 2 powder with an average particle size of 200–700 nm could be successfully prepared at low temperatures by adjusting the reduction temperature of MoO 3, ... Currently, the most commonly used method for the preparation of molybdenum powder is the hydrogen reduction of molybdenum oxide …
Yar et al. [18] prepared precursor powder with size of less than 20 μm and containing ultrafine Y particles.Then, the reduced power was sintered using SPS at a relatively low temperature. Room temperature ruptured surface of the sintered samples after various temperature shows in Fig. 3.The density and grain size of the materials were …
Ultrafine α-Al 2 O 3 particles with a high purity of 99.997% and an average size of 300–400 nm were successfully prepared via hydrothermal and jet-milling processes. The jet-milled Al 2 O 3 powders were coated on a conventional polyethylene (PE) separator, and the effects of the Al 2 O 3 particle size on the coating properties of the Al 2 O 3 …
Ultrafine powders are the hot spot of material science to be studied in 21st century and have commendable prospects of applications as developments of preparative technology. Aim The macro-properties, preparations and some recent applications of ultrafine powder are reviewed. Methods The interrelated data domestic and abroad are summarized.
Progress in preparation and application of ultrafine TiC powder. Titanium carbide (TiC) is a technologically important ceramic material.Due to its special properties,such as high melting point,extreme hardness,high wear resistance,chemical and thermal stability,titanium carbide has many potential applications.The method and characteristics of ...
At present, the research of ultrafine powder mainly includes four aspects: preparation, microstructure, macroscopic properties and application, among which the …
Authors and Affiliations. College of Engineering, Hosei University, 3-7-2 Kajinocho, Koganeishi, Tokyo, 184, Japan. Y. MORIYSOHI. National Institute for Research in ...
Ultrafine copper powder with uniform particle size and good dispersion was prepared in aqueous solution using copper oxide as precursor, ascorbic acid as reducing agent, …
Ultrafine tungsten carbide (WC) powder refers to WC powders with a particle size between 100 and 500 nm. Researchers have improved the comprehensive properties of WC-based cemented carbides by …
This study includes preparation of both coarse and ultrafine powder coatings to compare their film surface qualities, inner structures, leveling of powder during curing and corrosion protection abilities. ... The ultrafine powder coating panel demonstrates larger modulus of resistance at 0.01 Hz (8.0×10 10 Ω cm 2) than the …
The optimal preparation conditions for micronized HPC were obtained as follows: dropping speed of 4 mL/min, HPC solution concentration of 0.3 mg/mL, ratio of antisolvent and solvent of 5 mL/mL ...
Titanium diboride ultrafine powder was prepared from sucrose, tetrabutyl titanate and boric acid by the sol–gel and microwave carbothermal reduction method. The influence of reaction temperature, ratio of Ti to C and Ti to B on the synthesis of titanium diboride was studied. The results indicated that the carbothermal temperature, the …
DOI: 10.1016/S0254-0584(99)00015-2 Corpus ID: 94358918; Preparation of nickel ultrafine powder and crystalline film by chemical control reduction @article{Li1999PreparationON, title={Preparation of nickel ultrafine powder and crystalline film by chemical control reduction}, author={Yangming Li and Cun Li and Hui …
This paper intends to analyze the problems involved in the preparation of ultrafine powder from the point of view of chemical engineering and, based on this …
This article investigated the preparation of ultrafine W powder by fluidized bed hydrogen reduction, and the apparent activation energy was determined for various …
First, ultrafine pre-reduced tungsten-copper (W-Cu) powders containing a small amount of WO 2 were produced by reducing mixtures of CuWO 4 and WO 3 with …
The preparation of ultrafine copper powder with chemical reduction method was investigated. Ascorbic acid was employed as reducing agent. Reaction of CuSO4·5H2O with ascorbic acid at 70 °C gives ...
Preparation of ultrafine Sm 2 Fe 17 N 3 magnetic powders without ball milling. Author links open overlay panel Jing Wang a, Wei Cai a, Jingwu Zheng a, Junhui Zhu a, ... The powder was then rinsed three times with deionized water to remove residual weak acids on the surface of the powder. It was then washed three times with n-hexane …
Preparation and dispersive mechanism of highly dispersive ultrafine silver powder [J]. Applied Surface Science, 2010, 256: 6683âˆ'6687. [21] ZHANG Zong-tao, ZHAO Bin, HU Li-ming. PVP protective mechanism of ultrafine silver powder synthesized by chemical reduction processes [J]. Journal of Solid State Chemistry, 1996, 121: …
ABSTRACT. Ultrafine fish bone powder (UFBP) from silver carp (Hypophthalmichthys moli trix) was prepared using dry media milling.The characteristics of UFBP were investigated by a laser particle size analyzer, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), energy dispersive X-ray …
Preparation of ultrafine tungsten carbide powder by CVD method from WCl6–C2H2–H2 mixtures - Volume 8 Issue 10 ... The synthesis of ultrafine tungsten carbide powder from WCl 6 –C 2 H 2-H 2 mixtures was investigated. Under most experimental conditions, a mixture of α–WC and β–W 2 C was produced. The specific surface area and ...
Request PDF | On Jan 1, 2012, L.Y. Li and others published Preparation of ultrafine nickel powder by high-energy ball milling | Find, read and cite all the research you need on ResearchGate
Abstract. Ultrafine alumina power was obtained by calcining the precursor at 1 200 °C for 2 h, which was prepared by homogeneous precipitation method using aluminium salts and urea as raw materials. The effects of anions on the morphology, particle size, surface area and configuration of the precursors were studied.
Properties,Preparation and Application of Ultrafine Powder. Zhang Li-xin. Published 2001. Materials Science. Journal of North China Institute of Technology. TLDR. Ultrafine …
The preparation of metal-ceramic composite material, silver coated BaTiO3 powder, was investigated. The shape of single particle and congeries state were studied with SEM and laser particle size ...
