Method for preparing nano-silver wire with high length-diameter ratio

Abstract

The invention provides a method for preparing a nano-silver wire with high length-diameter ratio. At least one polyhydroxy liquid organic (1), silver nitrate (2), polyvinylpyrrolidone (PVP) with a K value equal to or larger than 30 (3), at least one hydrogen nitrate compound or one hydrogen-containing compound (4) and at least one chloride for a reaction solution, wherein the chloride can be dissolved in the polyhydroxy liquid organic and can produce chloride ions after dissolved. Reaction is perform for more than 10 minutes under the condition that the reaction temperature is lower than the boiling temperature of the polyhydroxy liquid organic or a part of ingredients is subjected to chemical reaction to form a nano-silver wire solution containing length-diameter ratio exceeding 200, and solid-liquid separation is performed to obtain the nano-silver wire or nano-silver wire dispersing liquid. The nano-silver wire prepared by means of the method is high in length-diameter ratio and yield, few in impurities and good in thickness and length uniformity, and the shortcomings including complicated preparing technology process by means of a traditional polyol method, many impurities and non-uniformity by means of a microwave method and the like are overcome.

Description

technical field [0001] The invention relates to the field of preparation of silver nanomaterials, in particular to a preparation method of nano silver wires with high aspect ratio. Background technique [0002] As an important branch of nanomaterial research, metal nanomaterials are represented by precious metals such as gold, silver, and copper, among which nanosilver has received the most attention because of its broad application prospects. Because nano silver has very stable physical and chemical properties, it has excellent performance in electronics, optics, antibacterial and catalysis, and can be widely used in catalyst materials, battery electrode materials, optical materials, antibacterial materials, coatings, etc. For example, nano-silver has high electrical conductivity and thermal conductivity, so that it can be used as a conductive filler for conductive adhesives. On the basis of obtaining better electrical conductivity, it can greatly reduce the amount of condu...

AI Technical Summary

Problems solved by technology

However, the polyol method has the following problems: 1) adopting a peristaltic pump to add silver nitrate and PVP solution simultaneously, the cost is high, and the adding time is long; 2) the preparation of nano-silver with different shapes requires adjustment of the dropping rate; 3 ) The process is complicated, which is not conducive to expanding production

All of the above methods can prepare silver nanowire materials, but the reaction conditions are very complicated, the reaction time is very long, generally takes 2 to 3 hours, the aspect ratio of the prepared silver nanowires is relatively small, and the yield is relatively low. ; or other particles need to be introduced, such as adding platinum nanoparticles as a catalyst during the reaction, resulting in impure products

The microwave method makes it possible to quickly prepare silver nanowire materials. Chinese patents: (1) A method for preparing silver nanowires in large quantities (application number: 200810019828.6), (2) a method for preparing noble metal nanowires in batches (application number For: 200810163102.X) (3) A microwave-assisted method for preparing silver nanostructure materials with different shapes (application number: 200910006131.X) (4) A method for preparing silver nanowires with controllable diameter by cation-controlled microwave method , (Application No.: 201010559335.9) respectively reported the preparation of nano-silver wire materials by microwave-assisted wet chemical method. Although the reported silver nano-wire materials can be prepared, the diameters of the prepared nano-silver wire materials are relatively short , generally no more than 30 microns, and the aspect ratio is relatively small. In this way, when preparing electrode materials, under the same filling rate, the silver nanowires with low aspect ratio will be larger than the silver nanowires with high aspect ratio due to the number of nodes. The number of lines is greatly increased, and its conductivity is an order of magnitude worse

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