Metal nanoparticles as lubricant additives
A lubricant composition comprising: (i) silver or gold nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules; (ii) palladium or platinum nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules; and (iii) a fluid in which components (i) and (ii) are present. Further described are methods for applying the lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction and wear reduction and/or corrosion inhibition.
1. A lubricant composition comprising:
(i) silver or gold nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules;
(ii) palladium or platinum nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules; and
(iii) a fluid in which components (i) and (ii) are present;
wherein said alkylthiol has the formula HS—(CH 2 ) n CH 3 and said alkylamine has the formula H 2 N—(CH 2 ) n CH 3 , wherein n is at least 3 and up to 22.
2. The lubricant composition of claim 1 , wherein said fluid is a base oil.
3. The lubricant composition of claim 2 , wherein said base oil is a mechanical lubricating oil.
4. The lubricant composition of claim 1 , wherein components (i) and (ii) are present in said fluid in a total amount of 0.1- 2 wt %.
5. The lubricant composition of claim 1 , wherein components (i) and (ii) are present in said fluid in a total amount of 0.1-1 wt %.
6. The lubricant composition of claim 1 , wherein component (ii) comprises palladium nanoparticles encapsulated by a layer of said alkylthiol or alkylamine molecules.
7. The lubricant composition of claim 1 , wherein nanoparticles in components (i) and (ii) are encapsulated by a layer of said alkylthiol molecules.
8. The lubricant composition of claim 1 , wherein nanoparticles in components (i) and (ii) independently have a size within a range of 1-50 nm.
9. The lubricant composition of claim 1 , wherein nanoparticles in components (i) and (ii) independently have a size within a range of 1-20 nm.
10. The lubricant composition of claim 1 , wherein nanoparticles in components (i) and (ii) independently have a size within a range of 1-10 nm.
11. The lubricant composition of claim 1 , wherein components (i) and (ii) are present in a weight ratio of 5:1 to 1:5.
12. The lubricant composition of claim 1 , wherein components (i) and (ii) are present in a weight ratio of 2:1 to 1:2.
13. The lubricant composition of claim 1 , wherein components (i) and (ii) are present in a weight ratio of about 1:1.
14. A method for reducing friction and wear in metal-containing mechanical components designed for movable contacting interaction with each other, the method comprising coating a lubricant composition on the mechanical components to result in reduced friction and wear when said mechanical components are in movable contacting operation, wherein said lubricant composition comprises:
(i) silver or gold nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules;
(ii) palladium or platinum nanoparticles, each of which is encapsulated by a layer of alkylthiol or alkylamine molecules; and
(iii) a fluid in which components (i) and (ii) are present;
wherein said alkylthiol has the formula HS—(CH 2 ) n CH 3 and said alkylamine has the formula H 2 N—(CH 2 ) n CH 3 , wherein n is at least 3 and up to 22.
15. The method of claim 14 , wherein said fluid is a base oil.
16. The method of claim 15 , wherein said base oil is a mechanical lubricating oil.
17. The method of claim 14 , wherein components (i) and (ii) are present in said fluid in a total amount of 0.1- 2 wt %.
18. The method of claim 14 , wherein components (i) and (ii) are present in said fluid in a total amount of 0.1- 1 wt %.
19. The method of claim 14 , wherein component (ii) comprises palladium nanoparticles encapsulated by a layer of said alkylthiol or alkylamine molecules.
20. The method of claim 14 , wherein nanoparticles in components (i) and (ii) are encapsulated by a layer of said alkylthiol molecules.
21. The method of claim 14 , wherein nanoparticles in components (i) and (ii) independently have a size within a range of 1-50 nm.
22. The method of claim 14 , wherein nanoparticles in components (i) and (ii) independently have a size within a range of 1-20 nm.
23. The method of claim 14 , wherein nanoparticles in components (i) and (ii) independently have a size within a range of 1-10 nm.
24. The method of claim 14 , wherein components (i) and (ii) are present in a weight ratio of 5:1 to 1:5.
25. The method of claim 14 , wherein components (i) and (ii) are present in a weight ratio of 2:1 to 1:2.
26. The method of claim 14 , wherein components (i) and (ii) are present in a weight ratio of about 1:1.
27. The lubricant composition of claim 1 , wherein component (i) comprises silver nanoparticles encapsulated by a layer of said alkylthiol or alkylamine molecules.
28. The method of claim 14 , wherein component (i) comprises silver nanoparticles encapsulated by a layer of said alkylthiol or alkylamine molecules.