How do nano lubricants affect mechanics of devices?
Lubrication is one of the fields which use nanotechnology. As the science advanced, we got to know different machinery. Same as science, the machines also went from macro to micro and then to nano. The path was obviously not an easy one. As the machines became smaller, we encountered the problem of lubrication of their parts. Lubrication is must for longevity of the device but it became a barrier as the scales of machinery became smaller.
Since ages lubrication has evolved as a science that involves physics, chemistry, contact mechanics and fluid mechanics. Nano lubrication is the science that controls adhesion, friction and wear of the surfaces that come in contact at nano scale. Nano sized lubricants are the agents which check all this.
Our understanding of lubrication from its traditional use is that lubrication is necessary to prevent wear and tear of the surface and also that some fluid pressure should be maintained to avoid the two surfaces from coming in contact. The fluids used provide hydrostatic and hydrodynamic pressures to support the load.
What are the important properties of lubricants of nano size?
For lubrication of two surfaces at nano scale, we require a long lasting surface film that may consist of one or two layers of particles.
Also ability of the film to withstand constant rubbing or repeated contact is important. To accomplish this one should keep in mind that the molecules of the film should not be non-degraded as the degradation may spoil parts of the device.
The film produced to serve the purpose of a nano lubricant should be self repairing. This means that if the particles from one part are removed by oxidation, evaporation or by contacts, the particles from other locations can move in and fill the space.
Temperature stability of nano lubricants is a must as the device may get heated up by constant rubbing.
Some other desirable factors are resistance to oxidation and decomposition.
It should be non-volatile to be effective.
The particles of this film should provide good adhesion and cohesion.
For example: Perfloropolyether or PFPE is one of the nano lubricants that is used in Magnetic head-disk lubrication. It is highly resistant to oxidation. It is non-volatile. It forms hydrogen bonding and provides good adhesion forces. It withstands high centrifugal forces that arise from disk rotation.
In modern day science we define nano lubrication as a means to obtaining control of friction, adhesion and wear and tear where the effect is controlled by the nano lubricants at the nano scale. Hence, use of these is very important for large firms dealing in mechanical part manufacture.