Lubricant additives, lubricant compositions, and applications of same
A lubricant composition includes a base lubricant and a plurality of lubricant additive molecules. Each molecule includes a surface active group attractable to a target surface, wherein the surface active group comprises a carboxyl group, a siloxyl group, an amine group, or a mixture thereof, and a carbon containing component connected to the surface active group, wherein the carbon containing component comprises a carbon ring, wherein the surface active group and the carbon containing component are adapted such that the carbon film is formed in situ on the target surface of the target machine only when tribological energy activates the lubricant additive to unravel the carbon containing component under a pressure and a temperature during operation.
1. A lubricant composition used for in situ forming a carbon film on a target surface of a target machine, comprising a base lubricant and a plurality of lubricant additive molecules, wherein each lubricant additive molecule comprises:
a surface active group attractable to a target surface, wherein the surface active group comprises a carboxyl group, a siloxyl group, an amine group, or a mixture thereof; and
a carbon containing component connected to the surface active group, wherein the carbon containing component comprises a carbon ring, such that operating the target machine causes a temperature and a pressure at the target surface so that the carbon containing component is unraveled thereon to form the carbon film in situ on the target surface during operation,
wherein the lubricant composition comprises cyclopropylacetic acid, cyclopropanol, or a mixture thereof.
2. The lubricant composition of claim 1 , comprising about 1-10 weight percentage (wt %) of the lubricant additive molecules.
3. The lubricant composition of claim 1 , wherein the lubricant additive binds to the target surface via polar (electrostatic) or chemical interactions through the surface active group.
4. The lubricant composition of claim 1 , wherein the temperature is in a range of 25° C.-500° C., and the pressure is in a range of 0.4-2 GPa.
5. The lubricant composition of claim 1 , wherein the carbon film comprises a plurality of graphitic sheets, amorphous and diamond-like carbon, or a mixture thereof.
6. The lubricant composition of claim 5 , wherein percentages of the graphitic sheets and the amorphous and diamond-like carbon in the carbon film depends on the temperature and the pressure at the target surface.
7. The lubricant composition of claim 6 , wherein the carbon film comprises substantially the graphitic sheet.
8. A lubricant composition used for in situ forming a carbon film on a target surface of a target machine, comprising a base lubricant and further comprising cyclopropylacetic acid, cyclopropanol, or a mixture thereof, such that operating the target machine causes a temperature and a pressure at the target surface so that carbon containing component of the lubricant composition is unraveled thereon to form the carbon film in situ on the target surface during operation.