Lubricant having nanoparticles and microparticles to enhance fuel efficiency, and a laser synthesis method to create dispersed nanoparticles

• US 20090042751A1
• Filed: 11/05/2007
• Published: 02/12/2009
• Est. Priority Date: 08/11/2007
• Status: Active Grant

• Current Assignee: Jagdish Narayan
• Original Assignee: Jagdish Narayan
• Inventors: Narayan, Jagdish
• Granted Patent: US 7,994,105 B2
• Time in Patent Office: Days
• US Class Current: 508/155
• CPC Class Codes: C10M 141/00 Lubricating compositions characterised by the additive being a mixture of two or more compounds covered by more than one of the main groups C10M125/00 - C10M139/00, each of these compounds being essential
• CPC Class Codes: C10M 2201/041 Carbon; Graphite; Carbon black
• CPC Class Codes: C10M 2201/05 Metals; Alloys
• CPC Class Codes: C10M 2201/06 Metal compounds of chromium C10M2201/086
• CPC Class Codes: C10M 2201/061 Carbides; Hydrides; Nitrides
• CPC Class Codes: C10M 2201/105 Silica
• CPC Class Codes: C10N 2010/06 Groups 3 or 13
• CPC Class Codes: C10N 2020/06 Particles of special shape or size
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2030/54 Fuel economy
• CPC Class Codes: C10N 2040/25 Internal-combustion engines
• CPC Class Codes: Y10S 977/773 Nanoparticle, i.e. structure having three dimensions of 100 nm or less

Abstract

A combination nano and microparticle treatment for engines enhances fuel efficiency and life duration and reduces exhaust emissions. The nanoparticles are chosen from a class of hard materials, preferably alumina, silica, ceria, titania, diamond, cubic boron nitride, and molybdenum oxide. The microparticles are chosen from a class of materials of layered structures, preferably graphite, hexagonal boron nitride, magnesium silicates (talc) and molybdenum disulphide. The nano-micro combination can be chosen from the same materials. This group of materials includes zinc oxide, copper oxide, molybdenum oxide, graphite, talc, and hexagonal boron nitride. The ratio of nano to micro in the proposed combination varies with the engine characteristics and driving conditions. A laser synthesis method can be used to disperse nanoparticles in engine oil or other compatible medium. The nano and microparticle combination when used in engine oil can effect surface morphology changes such as smoothening and polishing of engine wear surfaces, improvement in coefficient of friction, and fuel efficiency enhancement up to 35% in a variety of vehicles (cars and trucks) under actual road conditions, and reduction in exhaust emissions up to 90%.

Claims

1. A lubricant comprising:

hard nanoparticles having a size and hardness effective for embedding the hard nanoparticles in metal surfaces lubricated by the lubricant; and

soft microparticles having layered structures and a size and composition effective for filling voids in the lubricated surfaces.

2. The lubricant of claim 1, wherein the lubricant is an engine oil additive and the nanoparticles are effective to polish and grind the lubricated metal surfaces during operation of the engine.

3. The lubricant of claim 1, wherein the nanoparticles are alumina, silica, ceria, titania, diamond, cubic boron nitride, and molybdenum oxide having an average particle size of 5 to 100 nm.

4. The lubricant of claim 1, wherein the microparticles are of graphite, hexagonal boron nitride, magnesium silicates (talc) and molybdenum disulphide having an average particle size of 1 to 20 μ

m.

5. The lubricant of claim 1, wherein the nanoparticles comprise 10 to 80% of total nanoparticle plus microparticle content.

6. The lubricant of claim 3, wherein the nanoparticles and microparticles are of the same material selected from zinc oxide, copper oxide, molybdenum oxide, molybdenum disulphide, graphite, talc, and hexagonal boron nitride.

7. The lubricant of claim 1, wherein the nanoparticles are selected from alumina, silica, ceria, titania, diamond, cubic boron nitride, and molybdenum oxide and the microparticles are selected from graphite, hexagonal boron nitride, magnesium silicates (talc) and molybdenum disulphide.

8. The lubricant of claim 1, wherein the nanoparticles are produced by pulsed laser synthesis and the nanoparticles have a size of 5 to 100 nm.

9. The lubricant of claim 1, wherein the lubricant is an engine oil additive and the nanoparticles and microparticles comprise up to 10% by weight of the engine oil additive.

10. Engine oil containing the engine oil additive of claim 9, wherein the nanoparticles and microparticles are present in an amount of up to 1% by weight in the engine oil.

11. The engine oil of claim 10, wherein the engine oil is a 0W20, 5W20, 5W30 or 10-30 weight engine oil.

19. A method of manufacturing the lubricant of claim 1, comprising dispersing the hard nanoparticles in an oil medium by pulsed laser ablation of a target material and adding the soft layered microparticles to the oil medium with 1.0 to 10.0 wt. % concentration.

12. A method of reducing friction of wear surfaces comprising lubricating wear surfaces with lubricant containing hard nanoparticles and soft microparticles having layered structures wherein the nanoparticles are effective to polish the wear surfaces with at least some of the nanoparticles becoming embedded in the wear surfaces and the layered microparticles are effective to fill in voids in the wear surfaces.

13. The method of claim 12, wherein the lubricant is an engine oil and the coefficient of friction is reduced from a range of 0.2 to 0.4 to a range of 0.01 to 0.02 on cast iron and aluminum alloy wear surfaces.

14. The method of claim 13, wherein the engine oil reduces friction of the wear surfaces sufficiently to increase fuel efficiency by at least 10%.

15. The method of claim 13, wherein the engine oil reduces carbon dioxide emissions of the engine by at least 20%.

16. The method of claim 13, wherein the engine oil contains up to 1% by weight of the total nanoparticles plus microparticles content in the engine oil, the nanoparticles are alumina, silica, ceria, titania, diamond, cubic boron nitride, and molybdenum oxide having an average particle size of 5-100 nm and the microparticles are of graphite, hexagonal boron nitride, magnesium silicates (talc) and molybdenum disulphide.

17. The method of claim 13, wherein the nanoparticles and microparticles are of the same material selected from zinc oxide, copper oxide, molybdenum oxide, graphite, talc, and hexagonal boron nitride.

18. The method of claim 13, wherein the engine oil reduces emissions of carbon dioxide and carbon monoxide by at least 50% and up to 90% compared to the same engine oil without the engine oil additive.

20. The method of claim 18, further comprising adding the oil medium to engine oil with 0.02 to 0.2 wt. % by weight total of the hard nanoparticles and soft layered microparticles in the engine oil.