Disclosed herein are method and design rules for making polyelemental systems with specific heterostructures, including tetra-phase nanopartides with as many as six junctions. In accordance with an embodiment, a method of making a tetra-phase polyelemental nanoparticle using tri-phase nanoparticle architectures can include selecting two or more triphase nanoparticle architectures, wherein the two or more tri-phase nanoparticle architectures are one or more striped tri-phase architectures, one or more pie-shaped tri-phase architectures, or combinations thereof; identifying from the selected two or more tri-phase nanoparticle architectures groups of metals for generating each of the two or more tri-phase nanoparticle architectures; contacting a tip coated with an ink to a substrate to form a nanoreactor, the ink comprising block copolymer and the metals from the groups of metals identified for generating each of the two or more tri-phase nanoparticle architectures; and annealing the nanoreactors under conditions sufficient to synthesize a tetra-phase polyelemental nanoparticle.

A formulation containing particulate matter including nanometric metallic copper particles, at least 10% of the particulate matter being single-crystal metallic copper particles, the particulate matter having an average secondary particle size (d.sub.50) within a range of 20 to 200 nanometers, the nanometric metallic copper particles being at least partially covered by at least one dispersant; a concentration ratio of crystalline cuprous oxide particles to the nanometric metallic copper particles, within the particulate matter, being at most 0.4; the formulation including a solvent, the particulate matter and the solvent forming a dispersion.

A formulation containing particulate matter including nanometric metallic copper particles, at least 10% of the particulate matter being single-crystal metallic copper particles, the particulate matter having an average secondary particle size (d.sub.50) within a range of 20 to 200 nanometers, the nanometric metallic copper particles being at least partially covered by at least one dispersant; a concentration ratio of crystalline cuprous oxide particles to the nanometric metallic copper particles, within the particulate matter, being at most 0.4; the formulation including a solvent, the particulate matter and the solvent forming a dispersion.

A heat conductive paste including silver fine particles having an average particle diameter of primary particles of 40 to 350 nm, a crystallite diameter of 20 to 70 nm, and a ratio of the average particle diameter to the crystallite diameter of 1 to 5, an aliphatic primary amine and a compound having at least one phosphoric acid group. The heat conductive paste includes 1 to 40 parts by mass of the aliphatic primary amine and 0.001 to 2 parts by mass of the compound having at least one phosphoric acid group based on 100 parts by mass of the silver fine particles. The heat conductive paste has a high conductivity.

A method for purifying nanoparticles by which a large amount of nanoparticles can be obtained in a safe manner and in a short time as compared to a conventional method for purifying nanoparticles. A method for purifying nanoparticles by which nanoparticles are purified from a dispersion liquid in which nanoparticles are dispersed in a solvent A used in synthesis of the nanoparticles, the method including: a mixing step of mixing the dispersion liquid, a solvent B that is miscible with the solvent A, and a solvent C that forms two phases together with the solvent B; a concentrating step of concentrating the nanoparticles in a phase of the solvent C; a washing step of forming a third phase containing the nanoparticles in the phase of the solvent C; and a purifying step of extracting the third phase and removing the solvent C from the third phase.

A gear includes a sintered body, in which Fe is contained as a principal component, Ni is contained in a proportion of 2 mass % or more and 20 mass % or less, Si is contained in a proportion of 0.3 mass % or more and 5.0 mass % or less, C is contained in a proportion of 0.005 mass % or more and 0.3 mass % or less, and one element selected from the group consisting of Ti, V, Y, Zr, Nb, Hf, and Ta is defined as a first element, that is contained in a proportion of 0.01 mass % or more and 0.7 mass % or less.

A gear includes a sintered body, in which Fe is contained as a principal component, Ni is contained in a proportion of 2 mass % or more and 20 mass % or less, Si is contained in a proportion of 0.3 mass % or more and 5.0 mass % or less, C is contained in a proportion of 0.005 mass % or more and 0.3 mass % or less, and one element selected from the group consisting of Ti, V, Y, Zr, Nb, Hf, and Ta is defined as a first element, that is contained in a proportion of 0.01 mass % or more and 0.7 mass % or less.

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.

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.

The invention relates to a method of making a functionalized nanoparticle in an aqueous solution, wherein a chemical functionalization of a metal nanoparticle in the aqueous solution is provided and the aqueous solution comprises water and ingredients. The ingredients comprise at least the metal nanoparticle, a thiol of the form R—SH, where R represents a substituent, and a silver compound. The invention further relates to a plurality of functionalized nanoparticles according to the method, wherein each of the plurality of functionalized nanoparticles comprises a metal core, a silver coating and a sulfide bond substituent. The invention also relates to a lateral flow test method and device.