Embodiments of the present invention relate to methods for preparing high optical density solutions of nanoparticle, such as nanoplates, silver nanoplates or silver platelet nanoparticles, and to the solutions and substrates prepared by the methods. The process can include the addition of stabilizing agents (e.g., chemical or biological agents bound or otherwise linked to the nanoparticle surface) that stabilize the nanoparticle before, during, and/or after concentration, thereby allowing for the production of a stable, high optical density solution of silver nanoplates. The process can also include increasing the concentration of silver nanoplates within the solution, and thus increasing the solution optical density.

Disclosed is a method for preparing silver-copper mixed powder having a core-shell structure. The method includes: dissolving silver (Ag) and copper (Cu) in an aqueous nitric acid solution; adding a reducing agent to the solution; and preparing silver-copper mixed powder having a core-shell structure by performing plasma post-treatment, after performing the adding the reducing agent to the solution.

The sintered electrical contact material described in this specification includes at least one salt dispersed within a silver matrix, and no more than 100 ppm of cadmium and cadmium compounds. The sintered electrical contact material exhibit contact resistances much lower than than commercially available silver composites. The salts dispersed within the silver matrix represent a new class of additives for silver composites for high and low current applications.

The present invention refers to a method for the preparation of zero-valent-transition metal nanowires such as crystalline silver nanowires, and to a reactor oven for the preparation of zero-valent-transition metal nanowires.

The present invention relates to a metal wiring, to be formed on a flexible substrate, including a sintered body of silver particles. The sintered body constituting the metal wiring has a volume resistivity of 20 μΩ.Math.cm or less, hardness of 0.38 GPa or less, and a Young's modulus of 7.0 GPa or less. A conductive sheet provided with the metal wiring can be produced by applying/calcinating, on a substrate, a metal paste containing, as a solid content, silver particles having prescribed particle size and particle size distribution, and further containing, as a conditioner, an ethyl cellulose having a number average molecular weight of 10,000 or more and 90,000 or less. The metal wiring of the present invention is excellent in bending resistance with change in electrical characteristics suppressed even through repetitive bending deformation.

Provided is a composition for forming a plating base on which plating is applied without a pretreatment, especially any activation process for the plating base, conventionally believed to be necessary, as well as a thus-formed plating base and a method of forming a plating coat over the plating base. The plating base is a coating film formed by applying and drying a metal nanoparticle dispersion liquid or a metal nanoparticle dispersion ink in which metal nanoparticles are protected with a small amount of protecting agent. Thus, a metal film can be formed by plating without operations such as substrate cleaning or catalyst imparting and activating. Since it is not necessary to wash the substrate with acid or base solution or to heat-treat it at a high temperature, many variations of materials become available for the substrate.

A metallic nanoparticle dispersion includes metallic nanoparticles and a compound according to Formula I, ##STR00001##
wherein X represents the necessary atoms to form a substituted or unsubstituted ring. The presence of small amounts of the compound according to Formula I increases the conductivity of metallic layers or patterns formed from the metallic nanoparticle dispersions at moderate curing conditions.

A metallic nanoparticle composition includes metallic nanoparticles and a non-aqueous polar protic solvent. The non-aqueous polar protic solvent has two hydroxyl groups, a boiling point of at least 280° C. at 760 mm Hg, and a viscosity in a range of 45 cP to 65 cP at 20° C. Polyvinylpyrrolidone (PVP) is present on the metallic nanoparticle surfaces. A concentration of metals in the metallic nanoparticle composition is in a range of 60 wt% to 90 wt% and a concentration, in aggregate, of solvents having a boiling point of less than 280° C. at 760 mm Hg in the metallic nanoparticle composition does not exceed 3 wt%.

The present invention relates to a method for manufacturing gold nanoparticles, including: (a) placing a gold (Au) target on a magnet cathode and injecting argon (Ar) gas to generate plasma; (b) discharging powder of a compound having an non-shared electron pair upwardly in parallel to a vertical rotation axis inside a stirrer, followed by circulating and agitating the same up and down; and (c) ejecting the gold particles and binding the same to the compound having the non-shared electron pair, as well as gold nanoparticles manufactured by the same.

The present invention relates to a method for obtaining gold nanoparticles bound to niacinamide through vacuum deposition, which is generally used to form a thin film, wherein niacinamide is used by circulating and agitating the same up and down under special conditions, so as to produce high purity gold nanoparticles in high yield.

The present disclosure provides for metal nanoparticles, such as gold nanoparticles that have six pointed areas so that the metal nanoparticle resembles a six-pointed star. The distance from opposing points of the six-pointed star is about 400 to 480 nanometers. The present disclosure also provides for a method of making the nanoparticle, where in an aspect, the method is a light-driven synthesis.