To have a correct understanding of the various assumptions about nanodiamonds and even other types of so-called nanolubricants, we may first take a look at how nanomaterials (particles) are prepared.

As for nanodiamonds, similar to the preparation of nanometals, they are currently mainly obtained through the 'detonation method'. The detonation method is a technique that uses the instantaneous ultra-high temperature and high pressure generated by the explosion of negative oxygen balance explosives to rearrange and aggregate the released free carbon atoms to form nanodiamonds. The instantaneous nature of the detonation process determines that its product is ultrafine diamond with an average particle size of 4-10nm.

In fact, when it comes to so-called nanolubrication, the concept of 'thin film lubrication technology' cannot be ignored.

The emergence of nanoscience and technology is undoubtedly a major breakthrough in modern science and technology, giving rise to a series of new disciplines, including nanotribology. Nanotribology is the study of material interactions at the molecular scale, as well as the microscopic friction, wear, and lubrication behavior and mechanisms of surfaces during sliding processes. This is a significant expansion and deepening of tribology research. By using nanofilm lubrication and surface micro modification treatment, the goal of controlling friction and reducing wear can be achieved. Minimizing wear and tear is currently the key to the functionality and lifespan of certain high-tech equipment. It should be pointed out that tribology belongs to the field of surface science in terms of its performance, and its research object is the microscopic dynamic behavior and changes that occur on the friction surface and interface. The macroscopic characteristics exhibited by the material surface during the friction process are closely related to its atomic and molecular structure.

Macro tribology research plays an important role in reducing the frictional energy consumption of mechanical equipment, improving the wear resistance life and reliability, and promoting the development of machinery towards high parameter working conditions. It has become one of the important fundamental disciplines in modern mechanical design and manufacturing. In modern lubrication technology research, it has been found that in many low-speed, heavy-duty, high-temperature, and low viscosity lubricating media lubricated machinery and precision machinery, the lubricating film between friction pairs is often in a thin film lubrication state with a thickness of tens to tens of nanometers. The lubrication performance and mechanism in this state have not been fully understood, therefore, the research on thin film lubrication has become one of the important directions for the development of modern tribology, and the key issue is the measurement technology of nanoscale lubrication film thickness.

In the entire lubrication system, both the thickness and physical characteristics of the lubrication film indicate the existence of a transition zone between boundary lubrication and fluid lubrication (including fluid dynamic lubrication and elastic fluid lubrication). People naturally raise the question: What kind of lubrication state is the thickness of the lubricating film between the boundary film thickness and the elastohydrodynamic film thickness? How to transition from adsorption boundary film to elastic fluid film?

With the deepening development of elastohydrodynamic lubrication theory and its testing technology, a new lubrication state, thin film lubrication (thin film lubrication) state, has been proposed to describe the transition state between boundary thin film lubrication and fluid thin film lubrication. In the early 1990s, the existence of lubrication states characterized by submicron and nanometer scale film thickness was demonstrated both theoretically and practically, and important progress was made in the study of thin film lubrication performance and mechanism.