Provided is a block copolymer that makes it possible to produce inorganic nanoparticles that can be dispersed in an organic solvent, the inorganic nanoparticles being of uniform size and a reducing agent not having to be used. A block copolymer including a catechol segment represented by formula (1). ##STR00001##

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.

The present invention relates to a method for preparing a metal nanocube with a controlled corner sharpness index, comprising a step of reacting with a first surfactant and a predetermined surface-protecting agent; a method for preparing a metal nanocube aggregate having a purity of 95% or more, comprising a step of centrifuging in the presence of a second surfactant; a probe composition comprising the metal nanocube or metal nanocube aggregate prepared by the method; and a gold (Au) nanocube having an average edge length of 20 nm or less.

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. inyl 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.

The present disclosure is directed to methods for producing a single-walled carbon nanotube in a chemical vapor deposition (CVD) reactor. The methods comprise contacting liquid catalyst droplets and a carbon source in the reactor, and forming a single walled carbon nanotube at the surface of the liquid catalyst droplets.

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 sintering powder, wherein a least a portion of the particles making up the sintering powder comprise: a core comprising a first material; and a shell at least partially coating the core, the shell comprising a second material having a lower oxidation potential than the first material.

A method of forming monodispersed metal nanowires comprising: forming a reaction mixture including a metal salt, a capping agent and an ionic additive in a reducing solvent; and reducing the metal salt to the monodispersed metal nanostructures.

A silver powder, wherein the silver powder satisfies D.sub.50-IPA>D.sub.50-W, where in measurement of a volume-based particle size distribution of the silver powder by a laser diffraction particle size distribution analysis, D.sub.50-IPA (m) is a cumulative 50% point of particle diameter of the silver powder when isopropyl alcohol (IPA) is used as a measurement solvent for dispersing the silver powder, and D.sub.50-W (m) is a cumulative 50% point of particle diameter of the silver powder when water is used as a measurement solvent for dispersing the silver powder, and wherein a phosphorus content in the silver powder is 0.01% by mass or more but 0.3% by mass or less.

Disclosed is a method for manufacturing a metallic nanowire transparent electrode, including generating a metallic nanowire and chemically reducing the metallic nanowire to connect adjacent metallic nanowires.