CN114082976A

CN114082976A - Preparation method of high-crystallinity nano silver powder

Info

Publication number: CN114082976A
Application number: CN202111324250.7A
Authority: CN
Inventors: 李照枝
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-02-25

Abstract

The invention discloses a preparation method of high-crystallinity nano silver powder, which comprises the following steps: step 1: dissolving the Arabic gum powder and silver nitrate in deionized water to obtain a reaction system A; step 2: dissolving ascorbic acid in deionized water to obtain a reaction system B; and step 3: and quickly pouring the reaction system B into the reaction system A at a certain water bath temperature, and uniformly stirring to enable the reaction system A and the reaction system B to react for a certain time. Has the advantages that: the preparation process adopts the modes of rapid pouring and stirring to mix the reaction solution, thereby greatly reducing the preparation time and simplifying the preparation process, and further improving the preparation efficiency of the nano silver powder; the silver powder prepared by the method has high crystallinity, large tap density, good dispersibility and uniform particle size distribution; the preparation method disclosed by the invention has the advantages that the used reagents are few in types and are non-toxic and harmless to human bodies, and the safety of the nano silver powder in preparation is ensured.

Description

Preparation method of high-crystallinity nano silver powder

Technical Field

The invention relates to the technical field of micro-nano metal material preparation, in particular to a preparation method of high-crystallinity nano silver powder.

Background

Compared with a bulk material, the nano material has special physical effects such as quantum size effect, small size effect, surface effect and macroscopic quantum tunneling effect, presents unique optical, mechanical, magnetic, thermal and electrical characteristics, and is widely applied to the fields of information technology, energy environment, biomedical treatment and the like. This has prompted the preparation and application of nanomaterials to become a research hotspot of scientists.

The metal nano silver material as a representative of the nano material has excellent electrical properties, chemical stability, thermal properties, antibacterial properties and the like, is widely applied to surface enhanced Raman, transparent conductive films, sensing materials, catalytic materials, electronic circuits and the like, and has great market potential.

The progress of the nano silver material in the preparation technology promotes the miniaturization, simplification and integration development of electronic devices, and becomes the key of progress in many fields of modern science and technology.

At present, the traditional liquid phase chemical reduction method is mainly used for preparing the nano silver in the industry, the dripping is often adopted as a liquid adding mode to control the shape of the nano silver in the preparation, the consumed time is long, the preparation efficiency of the nano silver powder is low, simultaneously, the types of reagents used in the preparation are more, part of the reagents are harmful to human bodies, and the safety of the nano silver powder in the preparation is reduced.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the preparation method of the high-crystallinity nano silver powder, which adopts dumping as a liquid adding mode during preparation, utilizes the increase of the reaction speed at high temperature, completes the nucleation and crystallization steps of silver in a short time, can fully consume reactants, simplifies the preparation process, uses few types of reagents, and is non-toxic and harmless to human bodies.

The invention realizes the purpose through the following technical scheme:

a preparation method of high-crystallinity nano silver powder comprises the following steps:

step 1: dissolving the Arabic gum powder and silver nitrate in deionized water to obtain a reaction system A;

step 2: dissolving ascorbic acid in deionized water to obtain a reaction system B;

and step 3: quickly pouring the reaction system B into the reaction system A at a certain water bath temperature, and uniformly stirring to enable the reaction system A and the reaction system B to react for a certain time;

and 4, step 4: centrifuging, washing, drying and properly grinding the reacted suspension to obtain the high-crystallinity and high-dispersity nano silver powder;

and 5: and (4) packaging the nano silver powder prepared in the step (4) in bags, so that the nano silver powder can be put into use.

Further, when the reaction system A is prepared in the step 1, the silver salt is silver nitrate, and deionized water is used for preparing a silver nitrate solution with the concentration of 1.2-1.6 mol/L.

Further, when the reaction system A is prepared in the step 1, the surfactant is gum arabic powder, and the mass ratio of the gum arabic powder to the silver nitrate is 0.8.

Further, when the reaction system B is prepared in the step 2, the reducing agent is ascorbic acid, and deionized water is used for preparing an ascorbic acid solution with the substance concentration of 1-1.2 mol/L.

Further, in the step 3, a heat collection type magnetic stirrer is used for water bath stirring, the water bath temperature is 70 ℃, and the rotating speed is 1200 r/min.

Further, in the step 3, the reaction system B is poured into the reaction system A at a speed of 1L/s, the reaction time is 15-40min, wherein the reaction time is optimally controlled at 30 min.

Further, in the step 4, the drying temperature is 60 ℃, the drying time is 8-10h, and the drying time is preferably 8.5 h.

Further, a vertical centrifuge is adopted in the step 4 when the silver powder suspension is separated, the rotating speed is 3000r/min, and the rapid separation of the nano silver powder can be ensured.

The invention has the beneficial effects that:

1. the preparation process adopts the modes of rapid pouring and stirring to mix the reaction solution, thereby greatly reducing the preparation time and simplifying the preparation process, and further improving the preparation efficiency of the nano silver powder;

2. the silver powder prepared by the method has high crystallinity, large tap density, good dispersibility and uniform particle size distribution;

3. the preparation method disclosed by the invention has the advantages that the used reagents are few in types and are non-toxic and harmless to human bodies, and the safety of the nano silver powder in preparation is ensured.

Drawings

FIG. 1 is an SEM image of silver powder prepared by the method for preparing high-crystallinity nano silver powder.

Detailed Description

The following will further describe the process of preparing silver powder by the method of the present invention with reference to specific embodiments.

Examples

The preparation process of the nano silver powder is as follows:

step 1: weighing 4.92g of silver nitrate, dissolving the silver nitrate in 20mL of deionized water, weighing 3.94g of Arabic gum powder, and dissolving the Arabic gum powder in a silver nitrate solution to obtain a reaction system A;

step 2: weighing 2.55g of ascorbic acid and dissolving the ascorbic acid in 12m of ionized water to obtain a reaction system B;

and step 3: setting the water bath temperature to 70 ℃, quickly pouring the reaction system B to the reaction system A at the rotating speed of 1200r/min, and reacting for 30 min;

and 4, step 4: respectively centrifugally washing the mixed solution with absolute ethyl alcohol and deionized water for three times, then placing the washed mixed solution into a vacuum drying oven, setting the temperature at 60 ℃, drying for 8 hours, taking out the dried powder and properly grinding;

As can be seen from the measurement, the nano silver powder prepared by the method has the advantages of high crystallinity, large tap density, good dispersibility and uniform particle size distribution, and the microstructure of the nano silver powder is shown in figure 1.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A preparation method of high-crystallinity nano silver powder is characterized by comprising the following steps: it comprises the following steps:

step 2: dissolving ascorbic acid in deionized water to obtain a reaction system;

2. The method for preparing high-crystallinity nano silver powder according to claim 1, characterized in that: in the step 1, the concentration of the silver nitrate solution is 1.2-1.6mol/L, and the mass ratio of the Arabic gum powder to the silver nitrate is 0.8.

3. The method for preparing high-crystallinity nano silver powder according to claim 1, characterized in that: the concentration of the ascorbic acid solution in the step 2 is 1-1.2 mol/L.

4. The method for preparing high-crystallinity nano silver powder according to claim 1, characterized in that: in the step 3, a heat collection type magnetic stirrer is used for water bath stirring, the rotating speed is 1200r/min, the water bath temperature is 68-72 ℃, and the water bath temperature is preferably 70 ℃.

5. The method for preparing high-crystallinity nano silver powder according to claim 1, characterized in that: in the step 3, the reaction system B is poured into the reaction system A at the speed of 1L/s, and the reaction time is 15-40 min.

6. The method for preparing high-crystallinity nano silver powder according to claim 1, characterized in that: in the step 4, the drying temperature is 60 ℃, and the drying time is 8-10 h.

7. The method for preparing high-crystallinity nano silver powder according to claim 1, characterized in that: and 4, adopting a vertical centrifuge when separating the silver powder suspension in the step 4, wherein the rotating speed is 3000 r/min.