Methods of synthesizing gold nanodendrites (AuNDs) using amines, such as long chain amines, as a structural directing agent are disclosed. Degree of branching (DB) of the AuNDs can be tuned by adjusting certain synthetic parameters, such as solvent type, and the type and concentration of the long chain amines. DB control results in dramatic tunability of the optical properties of the AuNDs in the near infrared (NIR) range enabling improved performance, for example as a photothermal cancer therapeutic.

There are provided a spherical silver powder which has the same diameter as that of a spherical silver powder produced by a conventional wet reduction method and which can sufficiently sinter the silver particles thereof to cause the silver particles to be adhered to each other at a relatively low temperature to form a conductive film having a low volume resistivity when it is used for a baked type conductive paste, and a method for producing the same. A spherical silver powder, which contains a neutral or basic amino acid having a carbon number of not less than 5 in each of particles thereof and which has an average particle diameter D.sub.50 of 0.2 to 5 μm based on a laser diffraction method, is produced by adding the neutral or basic amino acid having the carbon number of not less than 5 (such as proline, tyrosine, tryptophan, phenylalanine, arginine or histidine) to a water reaction system containing silver ions to mix a reducing agent therewith to deposit silver particles by reduction.

This invention relates to the nano metal material preparation technology field, especially to the preparation method of one kind, of nano-rings. This invention uses polyvinyl pyrrolidone of different molecular weights as surface-protecting agent and dissolves silver nitrate in the low molecular weight polyvinyl pyrrolidone ethylene glycol solvent under frozen conditions. Frozen conditions can slow down or inhibit silver ions from being reduced to zero-valent silver, to generate silver nanoparticles coated and complexed with both low and high molecular weight polyvinyl pyrrolidone. Polyvinyl pyrrolidone of different molecular weight shows different selective absorption of silver, and different stability makes it affect the speed of growth of silver atoms along different crystal faces to different extent, which is better for silver nano-ring production, with higher yield. Silver nano-rings made from this invention features perfect circular shape, smooth surface, oval cross-section, and great crystal structure, and can be used as transparent flexible conductive material.

Methods for forming nanostructures of various shapes are disclosed. Nanocubes, nanowires, nanopyramids and multiply twinned particles of silver may by formed by combining a solution of silver nitrate in ethylene glycol with a solution of poly(vinyl pyrrolidone) in ethylene glycol. Hollow nanostructures may be formed by reacting a solution of solid nanostructures comprising one of a first metal and a first metal alloy with a metal salt that can be reduced by the first metal or first metal alloy. Nanostructures comprising a core with at least one nanoshell may be formed by plating a nanostructure and reacting the plating with a metal salt.

A fiber with metal ions excited by luminous energy and a manufacturing method thereof are provided. The method includes: adding dry copper nanopowder with a particle size not more than 48 nm after mixing to a fiber slurry, to form a first mixed liquid; mixing and stirring the first mixed liquid and an additive, and performing an electrochemical reaction, to form a second mixed liquid, where the additive contains at least one of graphene, Ge ions, and Zr ions; performing energy exciting on the second mixed liquid, to form a mixed material; drying the mixed material, to remove moisture contained in the mixed material; extruding at least one fibril from the mixed material by using a spinning device; passing the at least one fibril through a plurality of rollers and performing stretching; and performing cooling and shaping on at least one stretched fibril, to form a final fiber product.

A fiber with metal ions excited by luminous energy and a manufacturing method thereof are provided. The method includes: adding dry copper nanopowder with a particle size not more than 48 nm after mixing to a fiber slurry, to form a first mixed liquid; mixing and stirring the first mixed liquid and an additive, and performing an electrochemical reaction, to form a second mixed liquid, where the additive contains at least one of graphene, Ge ions, and Zr ions; performing energy exciting on the second mixed liquid, to form a mixed material; drying the mixed material, to remove moisture contained in the mixed material; extruding at least one fibril from the mixed material by using a spinning device; passing the at least one fibril through a plurality of rollers and performing stretching; and performing cooling and shaping on at least one stretched fibril, to form a final fiber product.

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 silver powder includes a large number of particles. The particles include polyhedral particles 2. The ratio P1 of the number of the polyhedral particles 2 to the total number of the particles is equal to or greater than 80%. Each polyhedral particle 2 has a body containing silver as a main component, and a coating layer covering a surface of the body and containing organic matter as a main component. Each polyhedral particle 2 has an aspect ratio of equal to or less than 3.0. The content P2 of the organic matter in the silver powder is preferably equal to or less than 0.5% by weight. The silver powder preferably has a median diameter D50 of equal to or less than 0.5 μm. The silver powder preferably has a tap density TD of equal to or greater than 5.0 g/cm.sup.3.

A solder-coated ball (10A) includes a spherical core containing Ni and P; and a solder layer (12) formed to coat the core (11). A solder-coated ball (10B) further includes a Cu plating layer (13) formed between the core (11) and the solder layer (12). A solder-coated ball (10C) further includes an Ni plating layer (14) formed between the Cu plating layer (13) and the solder layer (12).

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.