The present specification relates to a method for fabricating metal nanoparticles.

The invention relates to the rare metal smelting field, and particularly, the present invention relates to a tantalum powder for preparing capacitors and a process for preparing the tantalum powder, and to a sintered anode prepared from the tantalum powder. As to the tantalum powder as provided by the invention, its primary tantalum powder has a BET of from 3.0 to 4.5 m.sup.2/g. After the secondary agglomeration, the tantalum powder has a large particle size. The tantalum powder has an average Fisher sub-sieve size (FSSS) of 1.2 to 3.0 m wherein as measured with a standard sieve mesh, more than 75% of tantalum powder has a +325-mesh, and a particle size distribution D50 of more than 60 m, that is, the secondary particle size is high. A resultant capacitor anode prepared by sintering the tantalum powder of the invention at 1200 C. for 20 minutes and then being energized at the voltage of 20 V has the specific capacitance of from 140,000 to 180,000 FV/g and the residual current of less than 1.0 nA/FV. Meantime, the invention provides an economical process for making the tantalum powder.

Provided is a process for silver nanowire production in which the major-axis length of the silver nanowires can be controlled in a wide range and an agent for controlling the growth of silver nanowires. A process for silver nanowire production which is characterized in that an agent for controlling the growth of silver nanowires which comprises a polymer obtained by polymerizing one or more polymerizable monomers comprising an N-substituted (meth)acrylamide is reacted with a silver compound in a polyol at 25-180 C. The agent for controlling the growth of silver nanowires is characterized by comprising a polymer which has units of an N-substituted (meth)acrylamide as a polymerizable monomer.

The purpose of the present invention is to provide a metallic copper dispersion: capable of maintaining dispersion stability of metallic copper particles for a long period of time; suitable for inkjet printing, spray coating, or the like; and capable of allowing a metallic copper-containing film having an excellent electrical conductivity and metallic color tone to be manufactured in a simple manner by performing low-temperature heating or plasma irradiation after application. The metallic copper dispersion is a dispersion containing at least an organic solvent, a polymer dispersant, and metallic copper particles having gelatin on the particle surface, wherein the metallic copper particles in the dispersion have a cumulative 50% particle size (D50) of 1-130 nm and a cumulative 90% particle size (D90) of 10-300 nm, and the polymer dispersant has an amine number of 10-150 mgKOH/g. The metallic copper dispersion is manufactured by reducing copper oxide in an aqueous solvent in the presence of gelatin, then performing solid-liquid separation, and then mixing the obtained metallic copper particles having gelatin on the particle surface and the polymer dispersant into the organic solvent.

Provided a production method for reducing the content level of sulfur and carbon which are impurities in nickel powder to improve the quality of nickel powder produced by a complexing reduction method. The method of producing nickel powder having low carbon and sulfur concentrations includes: a complexing treatment of adding a complexing agent to a nickel sulfate aqueous solution to form a solution containing nickel complex ions; maintaining the solution containing nickel complex ions at a solution temperature of 150 to 250 C. in a pressure vessel and blowing hydrogen gas into the solution containing nickel complex ions to perform hydrogen reduction to produce nickel powder; washing the nickel powder with water; and then roasting the nickel powder washed with water in a mixed gas atmosphere of nitrogen and hydrogen.

A method of making a transparent conductive material includes: preparing a reactive solution that contains a solvent, a metal salt which is dissolved in the solvent, and a powder of graphene oxide which is dispersed in the solvent; and simultaneously reducing metal ions of the metal salt and the graphene oxide in the reactive solution to form a plurality of core-shell nanowires, each of which includes a core of a metal reduced from the metal ions, and a shell of graphene surrounding the core.

The present invention discloses a method for preparing nano-copper powder, comprising: (1) providing a dispersion solution, containing copper salt precursor and disperser, the disperser is dissoluble in both water and weak solvents, and is an acrylic modified polyurethane disperser; (2) providing a reducer dispersion solution, containing reducer, the reducer is organic borane; (3) contacting the reducer dispersion solution with the dispersion solution in a condition enough to reduce the copper salt precursor by the reducer into elementary copper; (4) separating copper nano-particles from reaction solution obtained by step (3), and drying separated copper nano-particles by spray drying, so as to obtain the nano-copper powder. The nano-copper powder prepared by the method in accordance with the present invention is dispersible in both water and environment-friendly weak solvents, which can be used to prepare weak solvent-type electrically conductive ink.

A concentrated dispersion of nanometric silver particles, and a method of producing the dispersion, the dispersion including a first solvent; a plurality of nanometric silver particles, in which a majority are single-crystal silver particles, the plurality of nanometric silver particles having an average secondary particle size (d.sub.50) within a range of 30 to 300 nanometers, the particles disposed within the solvent; and at least one dispersant; wherein a concentration of the silver particles within the dispersion is within a range of 30% to 75%, by weight, and wherein a concentration of the dispersant is within a range of 0.2% to 30% of the concentration of the silver particles, by weight.

The present specification relates to a method for preparing a metal nanoparticle.

Process to decrease silicon content of metal powder produced by hydrogen reduction from ammoniacal ammonium sulphate solutions containing metal ammine complexes, wherein metal (Me) is Ni, Co, or Cu. The process controls the precipitation of metal hydroxide, which is found to be an effective scavenger for silicon. Silicon is preferentially removed from metal diammine sulphate-containing solutions by precipitating with a small amount of a metal hydroxide, and then separating the silicon-bearing metal hydroxide precipitate from the solution. This solution, from which the silicon impurity has been removed with the metal hydroxide precipitate, can then be reduced in one or more densification cycles with a reducing gas to produce an elemental metal powder having a decreased silicon content. Alternatively, the solution is reduced to produce a low silicon metal powder seed material for the first of the one or more densification cycles.