Intermetallic nanoparticles
A process for preparing intermetallic nanoparticles of two or more metals is provided. In particular, the process includes the steps: a) dispersing nanoparticles of a first metal in a solvent to prepare a first metal solution, b) forming a reaction mixture with the first metal solution and a reducing agent, c) heating the reaction mixture to a reaction temperature; and d) adding a second metal solution containing a salt of a second metal to the reaction mixture. During this process, intermetallic nanoparticles, which contain a compound with the first and second metals are formed. The intermetallic nanoparticles with uniform size and a narrow size distribution is also provided. An electrochemical device such as a battery with the intermetallic nanoparticles is also provided.
1. A process comprising:
dispersing Sn nanoparticles in a solvent to prepare a first metal suspension;
forming a reaction mixture comprising the first metal solution and a reducing agent selected from the group consisting of phosphinates and hydrides;
adjusting the reaction mixture to a reaction temperature between about 50° C. and 200° C.; and
adding a second metal solution comprising a salt of Cu to the reaction mixture;
forming intermetallic nanoparticles are formed by reaction, the intermetallic nanoparticles comprising Sn and Cu.
2. The process of claim 1 , wherein the process is conducted under an inert atmosphere.
3. The process of claim 1 , wherein the Cu salt comprises sulfates, nitrates, chlorides, and acetates.
4. The process of claim 1 , wherein the reducing agent is selected from the group consisting of NaH 2 PO 2 , LiAlH 4 , sodium borohydride, citric acid, and ascorbic acid.
5. The process of claim 1 , wherein the reaction temperature is between about 50° C. to about 200° C.
6. The process of claim 1 , wherein the reaction temperature is between about 100° C. to about 150° C.
7. The process of claim 1 , further comprising cooling the reaction mixture to about room temperature occurs about 30 minutes after adding the Cu metal solution.
8. The process of claim 1 , wherein a crystal structure of the intermetallic nanoparticles differs from a crystal structure of the Sn metal and a crystal structure of the Cu metal.
9. The process of claim 1 , wherein the intermetallic nanoparticles have an average diameter from about 100 nm to about 400 nm.
10. The process of claim 1 , wherein the intermetallic nanoparticles have a polydispersity of about 0.2.
11. The process of claim 1 further comprising adding the intermetallic nanoparticles to a heat transfer fluid to form a heat transfer mixture whereby the thermal conductivity of the heat transfer mixture is greater than the thermal conductivity of the heat transfer fluid.
12. A process comprising:
dispersing Sn nanoparticles in a solvent to prepare a Sn suspension;
forming a reaction mixture, under an inert environment, comprising the Sn suspension and a phosphinate reducing agent;
adjusting the reaction mixture to a reaction temperature between about 100° C. and about 150° C.; and
adding a Cu metal solution comprising a salt of Cu to the reaction mixture;
agitating the reaction mixture;
cooling the reaction mixture to about room temperature;
wherein intermetallic nanoparticles of Cu 3 Sn are formed.
13. The process of claim 12 , wherein the phosphinate reducing agent is NaH 2 PO 2 *H 2 O.
14. The process of claim 12 , wherein the salt of copper is CuSO 4 *5H 2 O.
15. The process of claim 12 , wherein the cooling occurs about 30 minutes after adding the Cu metal solution.
16. The process of claim 12 , wherein the ratio (by weight) of Sn nanoparticles to CuSO 4 *5H 2 O is about 1.18 to 3.52 and wherein the reaction temperature is about 140° C.
17. A process comprising:
dispersing Sn nanoparticles in a solvent to prepare a Sn suspension;
forming a reaction mixture, under an inert environment, comprising the Sn suspension and a phosphinate reducing agent;
adjusting the reaction mixture to a reaction temperature between about 100° C. and about 150° C.; and
adding a Cu metal solution comprising a salt of Cu to the reaction mixture;
agitating the reaction mixture;
cooling the reaction mixture to about room temperature;
wherein intermetallic nanoparticles of Cu 6 Sn 5 are formed.
18. The process of claim 12 , wherein the phosphinate reducing agent is NaH 2 PO 2 *H 2 O.
19. The process of claim 12 , wherein the salt of copper is CuSO 4 *5H 2 O.
20. The process of claim 12 , wherein the cooling occurs about 30 minutes after adding the Cu metal solution.
21. The process of claim 12 , wherein the ratio (by weight) of Sn nanoparticles to CuSO 4 *5H 2 O is about 2.9 to 3.99 and wherein the reaction temperature is about 110° C.