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

Abstract

The invention discloses a method for preparing small-size nano-silver crystals through a linter blending-soaking-crystal cup method. Firstly, linters are planted into a crystal cup through high degree of carboxymethylation, then dried linters after high degree of carboxymethylation is evenly mixed with silver salt and solid reducing agents according to a certain ratio in a blending device, and then the mixed materials are soaked by water for complete reactions; the materials are dissolved in acid chlorine dioxide aqueous solution to be completely dissolved; the materials are filtered to obtain the main product, namely elemental silver crystals and the by-product, namely oligose. The method is simple and controllable in process, and prepared nano-silver has the advantages of being even in particle, small in size, narrow in particle size distribution range and good in nanometer effect. The main product, namely the elemental silver crystals are suitable for modifying electricity conductive, anti-static and antibacterial materials, or manufacturing modified fibers through the spinning method, and the by-product, namely the oligose is recovered and used as a nutrient carbohydrate source.

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 cotton linter blending-wetting-crystal seat method. Background technique [0002] It has been known in ancient my country that silver has the function of sterilizing and keeping fresh. In "Compendium of Materia Medica", there is a record of "raw silver, pungent, cold, and non-toxic". Li Shizhen said, "Silver is non-toxic, and its poison is the poison of all things and also". [0003] In 1884, German doctor F. Crede dripped 1% silver nitrate aqueous solution into the eyes of newborns to prevent blindness caused by neonatal conjunctivitis, thereby reducing the incidence of blindness in babies from 10% to 0.2%, which is called Crede prevention. Law. In 1893, C.Von Nageli of the United States reported for the first time the lethal effect of silver on bacteria and other lower organisms, making silver a disinfe...

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, and the particle size distribution is 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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