'Super-smooth' material eliminates friction from graphene and diamonds

Friction exists all around our lives. Without friction, you will not be able to stand on the floor, the keyboard and the computer will not stand still on the table for you to use . However, in many cases, friction is obstructing Operation of machinery, increasing corrosion rate . So, finding a material that can eliminate friction is a concern of many scientists.

Combined materials are almost frictionless

By combining a small amount of diamonds, a diamond-like carbon surface, and graphene, researchers from the Argonne National Laboratory of the US Department of Energy's Argonne National Laboratory have created a breakthrough when successfully making a combination material with superlubricity is almost frictionless. The promise of knowledge from this success will help create major improvements to mechanical systems such as machinery and turbines . The research is published in the Science journal.

To understand the research, let's learn a little about the cause of friction. At the atomic level, friction formed by mutual interference of atoms on two exposed surfaces makes it difficult to slip through each other. To make it easier to imagine, you can imagine these two contact surfaces zooming in like two carton egg cartons sliding over each other (see picture below).

Two carton egg boxes slide over each other

Thus, to eliminate friction, this effect must be eliminated. To do that, the team used three important components to combine together: diamond nanoparticles, a diamond-like carbon surface (DLC) and pieces. graphene.

Next, the team observed the interaction of graphene sheets with diamond nanoparticles as they rubbed on the surface of DLC. At that time, graphene rolled around diamond particles to create a tiny ball-like structure. The researchers call these structures nanoscrolls. These nanoscrolls can change direction during sliding, which will prevent two contact surfaces from being "locked " together when sliding on each other. This means that friction will then be removed. You can simply imagine this process as you place special balls between two layers of material to reduce friction between them as they move relative to each other.

The figure simulates the process of forming nanoscroll particles

To simulate the performance of these nanoscrolls , the team used supercomputers to perform large-scale atomistic computations. The results show that this effect is not only seen at the nanoscale but also at the macro level, at least theoretically.

Schematic of a test of super smooth properties

However, a minus point for this material is that this super-smooth property is only maintained in dry conditions, in a humid environment, it no longer holds these properties. Using calculations scientists discovered that the cause of this was because the existence of a layer of water would prevent the formation of nanoscroll balls, causing friction to increase.

Simulate the process of forming nanoscroll in dry and moist environment. You can see in the humid environment, the water layer prevents graphene pieces from surrounding diamond nanoparticles so the nanoscrolls are not formed.

Talking about the application and the importance of the study, the research team believes that detection will have a major impact on this area. Sanket Deshmukh, co-author of the study, said: 'The knowledge gained from this study will be very important in finding ways to reduce friction on everything from engines or turbines to discs. computer hardening and microelectromechanical systems'.