Stable nanometer silver colloidal sol and preparation method thereof

Abstract

The invention relates to a stable nanometer silver colloidal sol and a preparation method thereof. The stable nanometer silver colloidal sol adopts a silver containing compound, a protective agent and a solvent, water is used as the solvent, and the silver containing compound, the protective agent and the water are mixed so as to prepare the colloidal sol; and the particle diameters of nanometer silver grains are 1nm-10nm, and the nanometer silver grains are uniformly distributed in the colloidal sol, and can be preserved for 6 months to 24 months without changing at room temperature. The preparation method provided by the invention comprises the following steps of: adopting the silver containing compound and the protective agent as raw materials, adopting the water as the solvent, mixing the silver containing compound, the protective agent and the water so as to form a mixed solution which contains 200-10000ppm of silver, 0.02%-1% of protective agent, and the balance of water according to weight percent; and dissolving and mixing the components when the stable nanometer silver colloidal sol is prepared, then uniformly stirring, conducting ultrasonic processing, using a light source containing ultraviolet rays to light 30 minutes to 24 hours to obtain the nanometer silver colloidal sol containing the nanometer silver grains. The stable nanometer silver colloidal sol and the preparation method thereof provided by the invention have the advantages that the cost is low, the process is simple, and the stable nanometer silver colloidal sol is suitable for large-scale preparation.

Description

technical field [0001] The invention belongs to the technical field of nanometer metal sol, and in particular relates to a stable nanometer silver sol and a preparation method. Background technique [0002] Nano-silver has become a very active research field, and nano-silver has broad application prospects in antibacterial, electronics, sensors, catalysis, surface-enhanced Raman spectroscopy, etc. As far as the applicant knows, there are many methods reported in relevant technical literature for the preparation of nano silver, mainly including physical vapor deposition method, chemical reduction method, microemulsion method, electrochemical method gamma-ray radiation method, supercritical fluid method, etc. . All of the above methods can successfully prepare nanoscale silver particles, and have unique application properties. [0003] "A Nano-silver Colloid and Its Preparation Method and Their Use" (Application No.: CN200910091031.1) disclosed in Chinese patent literature, ...

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Problems solved by technology

In the three systems, the resonance absorption intensity of nano-silver decreases sequentially, the half-peak width increases sequentially, and the maximum absorption wavelengths are 400, 428 and 435nm respectively. The particles formed are all spherical structures without agglomeration phenomenon, but the average particle size and particle size distribution of the particles There is a clear difference

[0007] The applicant found in the research that these methods all have certain deficiencies in varying degrees: for example, the reducing agent (such as hydrazine hydrate, sodium borohydride, etc.) used in the chemical reduction method is toxic, and the particle size distribution of the prepared silver nanoparticles is not uniform. , which limits the use of nano-silver; and the preparation of nano-scale silver particles by chemical vapor deposition, supercritical fluid, magnetron sputtering, laser ablation and γ-ray radiation requires high equipment requirements; Nano-scale silver particles are prepared by microemulsion method and seed medium method, and the process is cumbersome; the preparation speed of nano-scale silver particles is prepared by electrochemical method, and the preparation speed is slow, and a high concentration of protective agent must be added, and there are many large particle sizes. The silver particles are deposited on the cathode, which increases the cost of preparing nano silver

But as far as the applicant knows, there is no nano-silver sol in the prior art that can meet this requirement

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