A method for preparing small-sized nano-silver crystals by blending-wetting-crystal seat method

Abstract

The invention discloses a method for preparing small-sized nanometer silver crystals through a blending-soaking-crystallizing method. The method includes the steps of firstly, evenly mixing sodium alginate powder with silver salt and solid reductant in a blending device; secondly, slowly soaking materials in deionized water, and conducting controlling to prevent water leakage in the soaking process; thirdly, keeping moisture in a sealed mode, conducting a reaction statically for 1 hour to 48 hours, and preparing semi-dry materials; fourthly, dissolving the semi-dry materials in an alkaline chlorine dioxide solution till the semi-dry materials are completely dissolved; fifthly, conducting refiltering or high-speed centrifugation, and then obtaining single-substance silver crystals as the main product and low-molecular-weight sodium alginate as the auxiliary product. The method is simple and controllable in process; the prepared nanometer silver has the advantages of being small in size, narrow in granularity distribution range and excellent in nanometer effect. The main product, namely, the silver crystals, is suitable for modifying electrically-conductive antistatic and antibacterial materials or manufacturing fiber modified through the spinning method; the auxiliary product is recycled to be used as fertilizers.

Description

technical field [0001] The invention relates to a preparation method of nano-silver crystals, in particular to a method for preparing small-sized nano-silver crystals by a blending-wetting-crystal seat method. Background technique [0002] Nanosilver is used as an antibacterial agent in many applications, for example, in mobile phones, keyboards, mice, air cleaners, filter materials, refrigerators, freezers, washing machines, kitchen cleaning products, children's toys, baby bottles, door handles, toothbrushes, public transportation Tool upholstery, bedding, underwear, socks, shirts, coats, gloves, hats, etc., the application field is very wide. Therefore, nanosilver has rapidly become one of the most commonly used nanomaterials in daily consumer products, and it is also the fastest growing material in the field of commercialization of nanomaterials. [0003] Nano-silver has broad-spectrum antibacterial properties and can kill various pathogenic microorganisms. It is a stron...

AI Technical Summary

Problems solved by technology

[0012] (1) The physical method not only has high energy consumption, complex and expensive equipment, but also complicated control of process conditions; the size of the product silver is actually difficult to reach the nanometer level, or the particle size distribution is relatively wide;

[0013] (2) react under low concentration conditions in the aqueous phase, the reaction efficiency is low, and the water consumption is large;

[0014] (3) A variety of stabilizers and modifiers are required, among which polyvinyl alcohol (PVA), sodium dodecyl sulfate (DBS), dodecyl mercaptan, quaternary ammonium salts, etc. are not biodegradable; Diphenol, sodium borocyanide, hydrazine hydrate, and hexamethylenetetramine are all toxic; the use of hydrogen is prone to explosion accidents, and there are potential safety hazards

Therefore, none of the above methods belong to the green chemical process;

[0015] (4) The particle size of the prepared nano-silver particles is mostly 50nm and above, and it is difficult to obtain a nano-silver crystal product with a narrow distribution of about 10nm, and the nano-effect is relatively low;

[0016] (5) The nano-silver colloid prepared by the above-mentioned method is used in the finishing of textiles and needs to use chemicals such as adhesives and surface modifiers, which not only causes chemical pollution, but also inevitably, due to the need to introduce adhesives, will Lead to changes in the surface properties of nanoparticles, greatly reducing nano-effects, weakening antibacterial and other functions

Moreover, due to the coating finishing, the durability of antibacterial and other functions is also poor.

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