Lubricant, friction pair having the lubricant and method for controlling friction coefficient between the friction pair

1. A method for controlling a friction coefficient between a friction pair, wherein the friction pair comprises a first friction part and a second friction part, and the method comprises:

providing a lubricant between the first and second friction parts;

applying a potential on the first friction part and adjusting the potential of the first friction part by an electrode system, in which the first friction part is used as a working electrode; and

adjusting the friction coefficient by adjusting the potential of the first friction part,

wherein the lubricant comprises propylene carbonate as a solvent and a surfactant,

wherein the lubricant is a solution of sodium dodecyl sulfate in propylene carbonate, and the sodium dodecyl sulfate has a concentration selected from: 0.1 mM, 0.5 mM, 1 mM and 2 mM.

2. The method according to claim 1 , further comprising

subjecting the lubricant to an ultrasonication at a temperature ranging from 40° C. to about 50° C.

3. The method according to claim 1 , wherein the first friction part is made of metal.

4. The method according to claim 1 , wherein the second part is made of metal.

5. The method according to claim 1 , wherein the second part is made of ceramic.

6. The method according to claim 1 , wherein the potential is applied on the first friction part by an electrode system, and the electrode system comprises:

a working electrode, wherein the first friction part is used as the working electrode;

a counter electrode made from inert material and adapted to provide a current channel for the wording electrode; and

a reference electrode adapted to provide a potential channel for the working electrode.