graphene slipperiness

Graphene – A slippery little thing.

In manufacturing self-lubricating components for the tool and die industry, the SelfLube Company uses graphite and graphene in their everyday business. Graphite, which has been used since ancient times, was always thought to be pretty well understood –  but the reality is it has always been a strange substance. It is one of the few materials that doesn’t expand when heated or shrink when cooled (i.e., it has zero coefficient of linear expansion). It isn’t a metal, but it conducts electricity like a metal. And, when reduced to a single layer, Graphene, the name given to a single sheet of graphite, turns out to be the strongest material known – 100 times stronger than steel. It is not just a good conductor of electricity; it is the best-known conductor of electricity. And, it is slippery, very slippery.

The report, from theorists at the National Institute of Standards and Technology (NIST), suggests how graphene’s friction is reduced as more layers are added to a stack.

The researchers, using a software modelling programme that simulates atomic force microscopy,  found that graphene deflects under and around the AFM tip. The localized, temporary warping creates rolling friction or resistance, the force that exerts drag on a circular object rolling along a surface. With fewer layers, the top layer deflects more, and the friction per unit of AFM contact force rises. The top surface of the stack becomes less yielding and more slippery as graphene layers are added. By contrast, the friction of three-dimensional graphite-like material is virtually unaffected by deformation and rolling friction, and is due instead to heat created by the moving tip.

With the capacity to be folded, rolled or stacked, graphene is super-strong and has unusual electronic and optical properties. The material might be used in applications ranging from electronic circuits to solar cells to “greasing” moving parts in nanoscale devices Phil Allor, CEO of SelfLube, points out that

“SelfLube has been ahead of the curve on this, using graphite/graphene and it’s amazing properties as a super-lubricant for many years. There is no telling where this will lead us in the future.”

As the market develops it would be wise to keep one’s eyes open for opportunities such as this. Graphene’s unique array of properties make it remarkably versatile, and so as the price comes down due to new production techniques and scalability, those small to medium sized companies already having a foothold in the science are the one’s most likely to float on the stock-market. SelfLube has not as yet declared an interest in releasing shares for sale, but it is certainly one to watch.

 

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