# US 10,500,637 B2 · Silver-chromium alloy nanowire and preparation method therefor

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- Number: US 10,500,637 B2
- Document ID: US10500637B2
- Status: Granted
- Kind: B2
- Application number: 15/571,852
- Filed: 2015-06-04
- Published: 2018-05-24
- Granted: 2019-12-10
- Earliest claimed: 2015-05-28
- Assignees: Beijing University of Chemical Technology
- Applicants: Beijing University of Chemical Technology
- Inventors: Xiaoming Sun; Cheng Wang
- Web page: https://patentgrep.com/patent/US10500637B2

## CPC

- B22F 9/24: starting from liquid metal compounds, e.g. solutions
- B22F 1/00: Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
- B22F 1/0547: {Nanofibres or nanotubes}
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- B82Y 40/00: Manufacture or treatment of nanostructures
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

The invention discloses a silver-chromium alloy nanowire having a diameter of 18 to 60 nm, a length of 5 to 100 μm, wherein a molar ratio of the silver to chromium is 1:0.01-3. The preparation method of the silver-chromium alloy nanowire comprises the steps of: a. preparing a reaction solution: formulating a silver source, a chromium source, polyvinylpyrrolidone and a reductive agent into a reaction solution, or adding the materials into deionized water to formulate a reaction solution; and b. performing a reductive reaction: performing a reductive reaction by maintaining the reaction vessel at a temperature of 120° C. to 200° C. for 2-10 hours to obtain a silver-chromium alloy nanowire suspension. The minimum diameter of the silver-chromium alloy nanowire of the present invention may reach 18 nm and its length is usually 20 μm or above. Thus, it has a broad application prospect.

## Claims

### Claim 1

A silver-chromium alloy nanowire, wherein the silver-chromium alloy nanowire has a diameter of 18 to 50 nm, and a length of 5 to 100 μm, wherein a molar ratio of silver to chromium is 1:1-3.

### Claim 2

A method for preparing a silver-chromium alloy nanowire, wherein the silver-chromium alloy nanowire has a diameter of 18 to 50 nm, and a length of 5 to 100 μm, a molar ratio of silver to chromium is 1:1-3, the method comprises the following steps:
a. preparing a reaction solution: formulating a silver source, a chromium source, polyvinylpyrrolidone and a reductive agent into a reaction solution, or adding the silver source, chromium source, polyvinylpyrrolidone and reductive agent into deionized water to formulate the reaction solution, wherein a molar ratio of silver ions in the silver source to chromium ions in the chromium source is 1:0.01-3; adding the reaction solution into a reaction vessel;
b. performing a reductive reaction: performing a reductive reaction by maintaining the reaction vessel at a temperature of 120° C. to 200° C. for 2 to 10 hours, to obtain a silver-chromium alloy nanowire suspension.

### Claim 3 (depends on 2)

The method according to claim 2, wherein after the step b, the method further comprises the following step c: centrifugation concentrating the silver-chromium alloy nanowire suspension to obtain a concentrated silver-chromium alloy nanowire suspension.

### Claim 4 (depends on 2)

The method according to claim 2, wherein the silver source is selected from the group consisting of silver nitrate, silver oxalate and silver acetate; wherein the chromium source is selected from the group consisting of chromium sulfate, chromium chloride and chromium nitrate; wherein the reductive agent is selected from the group consisting of polyol, formamide, hexamethylenetetraamine and glucose; wherein the polyol is selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,4-butanediol and hexanediol.

### Claim 5 (depends on 2)

The method according to claim 2, wherein the reductive reaction is performed under an autogenous pressure in a closed reaction vessel or the reductive reaction is performed under a normal pressure in an opening reaction vessel.

### Claim 6 (depends on 5)

The method according to claim 5, wherein the reaction solution is added into the reaction vessel at once or a portion of the reaction solution is firstly added into the opening reaction vessel, and then the left portion of the reaction solution is added into the opening reaction vessel in portions during the reaction.

### Claim 7 (depends on 2)

The method according to claim 2, wherein the reaction solution further comprises a nucleation controlling agent, wherein the nucleation controlling agent is selected from the group consisting of alkali metal halides, alkaline earth metal halides, alkali metal silicates, alkaline earth metal silicates, alkali metal sulfates, alkaline earth metal sulfates, alkali metal thiocyanates, alkaline earth metal thiocyanates, alkali metal oxalates, alkaline earth metal oxalates, alkali metal sulfides and alkaline earth metal sulfides.

### Claim 8 (depends on 4)

The method according to claim 4, wherein when the reductive agent is polyol, a volume ratio of the polyol to the deionized water is 1:0-10;
wherein when the reductive agent is formamide or glucose, a molar ratio of the silver ions in the silver source to the reductive agent is 1:2.7-20, and a molar ratio of the chromium ions in the chromium source to the reductive agent is 1:3-30;
wherein when the reductive agent is hexamethylenetetraamine, a molar ratio of the silver ions in the silver source to the reductive agent is 1:0.7-5, and a molar ratio of the chromium ions in the chromium source to the reductive agent is 1:0.8-8.

### Claim 9 (depends on 2)

The method according to claim 2, wherein a diameter of the silver-chromium alloy nanowire is reduced by reducing a molar ratio of Ag/Cr.