KR20000012423A - Manufacturing of Metallic Nanoparticles in Surfactant Solutions - Google Patents

Abstract

PURPOSE: A manufacturing method of a fine metal particle is provided to maximize the efficiency when mixing with other materials or singly using for the purposes of antibiotic, sterilizing, polishing, preventing electrification, catalytic, blocking an electronic wave, electric/electronic material and sensitizing and to prevent the performance from decreasing since the metal particle is changed to an oxidized substance by contacting with water. CONSTITUTION: A manufacturing method of a fine metal particle is comprised of the steps of: manufacturing a solution 1 by adding a metal ion reducer such as an organic material included with Hydrazine, LiAIBH4, NaBH4 and ethylene oxide group; manufacturing a solution 2 by dissolving an aqueous salt capable of bringing out the metal particle ion to manufacture; and converting the metal ion to a metal atom by reducing if slowly adding up the solution 1 in the solution 2 while agitating; adding up a proper amount of a surface active agent in a solution formed with a particle.

Description

Manufacturing Method of Micro Metallic Particles in Surfactant Aqueous Solution {Manufacturing of Metallic Nanoparticles in Surfactant Solutions}

When the particle size is reduced to fine units (300 nm or less) in the particle utilization technology, the physical properties and performance of the particle are very different from those when the particle size is larger than or equal to μm. This is due to the increase in the surface-to-mass ratio of the particles, which increases the surface area per unit mass, which improves the performance of the particles, decreases the melting point of the particles, and changes the properties of the particles. Has different properties.

In addition, it is also very important to make the size of the particles formed as small as the particles in the technology of particle utilization. If the particle size is non-uniform, each particle has different performance and physical properties, thereby limiting its application to advanced fields. For example, particle-type materials are used in a wide range of fields such as catalysts, sensors, information recording media (magnetic materials), abrasives (including chemical mechanical polishing), antibacterial and sterilizing particles, pharmaceuticals, electromagnetic shielding purposes, and display fields (phosphors). There is an active research to produce a small and uniform size of.

In the present invention, metal particles such as gold (Au), silver (Ag), copper (Cu), platinum (Pt), palladium (Pd), zinc (Zn) and iron (Fe) utilize the solid adsorption properties of the surfactant. To a fine size (300 nm or less) in an aqueous solution in an economical process. At this time, when the surfactant is formed from metal ions by reduction from metal ions to serve to control the size and size distribution of the particles. Because of the inherent nature of the surfactant molecules to adsorb to the interface, they are adsorbed on the surface of the metal particle nuclei in the solution in which the metal particles are formed, thereby preventing the nuclei from fusing together. It serves to make fine metal particles with a uniform distribution.

In addition, the micrometal particles produced by this method react with oxygen or oxygen for a long time to be converted into oxides, resulting in deterioration of particle performance, but using micrometal particles with antioxidants for the purpose of preventing oxidation of metal particles. It is part of the present invention.

In the present invention, by producing the fine metal particles in the aqueous solution of the surfactant, the particle size distribution formed according to the type and concentration of the surfactant is uniform at 300 nm or less, and these particles are antimicrobial, sterilizing, polishing, antistatic, catalyst, electromagnetic wave It is aimed at maximizing the effect when used alone or in combination with other materials for blocking, electric / electronic materials, and photosensitive purposes, and preventing the metal particles from converting into oxides by deterioration in contact with air or moisture.

The technical field to which the present invention belongs is a field for producing and utilizing fine metal particles, and the conventional methods for preparing fine metal particles include various methods such as mechanical grinding, coprecipitation, spraying, sol-gel, electrolysis, and reverse phase microemulsion. However, such a manufacturing method has a problem in that it is difficult to control the size of the particles to be formed or a lot of expense is required when producing fine metal particles. For example, the coprecipitation method is similar to the present invention, but it is impossible to control the size, shape, and size distribution of particles by preparing particles in an aqueous solution without a surfactant, but metal particle manufacturing technology is widely used at present. Electrolysis and sol-gel methods are expensive to manufacture and difficult to mass-produce. In reverse microemulsion, the size, shape, and size distribution of particles are easily controlled, but the manufacturing process is very complicated, and thus they are not put to practical use.

The technical problem to be achieved by the present invention is the following three.

① Production of economical fine metal particles

To achieve mass production of fine metal particles with uniform size distribution in an economical and simple process. Conventional fine metal particle manufacturing technology is very disadvantageous in terms of mass production and cost, but the present invention is a simple metal particle manufacturing process is simple and the size of the formed particle size, concentration, working temperature, conditions of aqueous solution (pH) Easily adjusted with simple changes to your back.

② Utilization of effective micrometallic particles

The fine metal particles prepared by the above method are dispersed in a polymer film or other medium, and then attached to the antimicrobial and sterilizing purposes, abrasives, medicinal, antistatic films or packaging materials, electromagnetic wave blocking films and polymer films, and used for photosensitive purposes. Maximize performance.

③ Continuous performance of fine metal particles

Disperses the prepared fine metal particles into a polymer film and turns them into oxides in contact with oxygen when used for various purposes, and the performance decreases with time, but by adding antioxidants to prevent their oxidation, the performance of the particles is sustained for a long time. .

A water-soluble Ag salt, Cu salt, Au salt, Fe salt, Pt salt, Pd salt, and a salt capable of producing ions of the fine metal particles to be prepared are dissolved in an aqueous solution. In other aqueous solution, one or two or more substances and surfactants among hydrazine, NaBH ₄ , LiAlBH ₄ , oxo compound, and other reducing agents are dissolved in an aqueous solution, and then the solution containing salt is added slowly, while the type of surfactant is added. Microparticles with different size and size distribution are prepared according to the concentration and concentration. Surfactants which can be added here include all kinds of surfactants such as nonionic, anionic, cationic, amphoteric hydrocarbons, silicones, and fluorocarbons.

For example, one of the methods for producing fine silver (Ag) particles by the above technique is as follows. While slowly stirring 1.25 grams (g) of polyoxyethylene (20 mol) sorbitan monolaurate (Tween20) and 100 grams of water in which 0.07 grams of hydrazine is dissolved, 5 grams of aqueous solution in which 0.04 grams of AgNO ₃ is dissolved is gradually added. Fine silver particles having an average diameter of 50 nm are prepared and have a light yellow color when dispersed in an aqueous solution.

The particles produced in this way have a uniform and fine size distribution and are dispersed in a polymer film or other media to maximize the effectiveness of antimicrobial and antiseptic, antistatic, electromagnetic wave blocking, photosensitive, and catalytic purposes. Maintain particle performance for a long time.

In the effect of the present invention

-Mass production of various fine metal particles with economical and simple manufacturing process

-The particle size is fine (300 nm or less) and the size distribution is uniform, so the particle performance is excellent.

-As the particle size is small, the appearance of the film remains transparent or translucent when dispersed in the polymer film.

-By using with antioxidant to prevent oxidation of metal particles, the performance of fine metal particles can be maintained for a long time.

Claims (4)

In preparing the metal particles using the surfactant, preparing a solution I by adding a metal ion reducing agent such as Hydrazine, LiAlBH ₄ , NaBH _4, an organic material containing an ethylene oxide group to the aqueous solution of the surfactant, Water-soluble salts capable of generating ions of metal particles such as AgNO ₃ or Ag (O ₂ C ₂ H ₃ ) for silver particles, FeCl _{3 for} iron particles, CuNO _{3 for} copper particles, and so on Preparing a solution II, gradually adding the solution II while stirring the solution I, converting the metal ions into metal atoms, and adding an appropriate amount of the surfactant to the aqueous solution in which the particles are formed. Particle preparation method. The method of claim 1, wherein the metal particles used in controlling the size and distribution of the particles are gold (Au), silver (Ag), copper (Cu), iron (Fe), platinum (Pt), palladium (Pd), Zinc (Zn) and surfactants are nonionic, cationic, anionic, amphoteric hydrocarbon-based, silicone-based, or fluorocarbon-based, and are further converted into oxides in contact with air or moisture to prevent performance degradation. In order to utilize the fine metal particles, characterized in that using an antioxidant such as Butylhydroxytoluene, vitamin E derivatives. To prepare a film by dispersing the fine metal particles prepared by the method of claim 1 alone or in a mixture of two or more metal particles in a polymer film such as polyester, polyethylene, polypropylene, polyurethane, polyvinylchloride, polyacrylate, acrylonitrile-butadiene-styrene, etc. Characterized in that it is used. Antimicrobial and sterilization of the fine metal particles produced by the method of claim 1 alone or a mixture of two or more metal particles, for pharmaceuticals, abrasives (including chemical mechanical polishing), antistatic, electromagnetic wave blocking, electrical / electronic materials, photosensitization, catalysts, etc. Method for use for the purpose of.