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Graphene is the super substance that could replace silicon, plastic and glass

Marco Chiappetta | April 30, 2014
A single atom thick, yet strong as steel and hard as a diamond, graphene could change how we build technology. If we can figure out how to manufacture it.

Graphene

The silicon, plastic, and glass that make up much of our tech these days could soon be replaced with something old, yet completely new: Graphene.

If graphene sounds like something that could fell a superhero, you're almost right. It's the thinnest substance known to science, yet it's 300 times stronger than steel and harder than a diamond. High-quality graphene is also transparent and flexible, and it's an excellent conductor of heat and electricity.

We've known of graphene's existence since the mid-1800s, but scientists have been able to experiment with graphene only in the past decade. In 2004, two researchers at the University of Manchester isolated graphene for the very first time, using--believe it or not--a chunk of graphite and a roll of adhesive tape.

So what exactly is graphene?

Graphene is a crystalline structure composed entirely of carbon atoms, arranged in a hexagonal, honeycomb-like pattern. Graphene's single-atom thinness (meaning it has length and width, but no height) makes it as close to 2D as any substance can be.

Graphene is also a fundamental component of other allotropes (structurally different forms of the element carbon). These include charcoal, carbon nanotubes, and other fullerenes (molecules composed solely of carbon).

It is graphene's unique structure and composition that endows it with so many valuable properties. Carbon atoms have four electrons in their outer shell, three of which form strong covalent bonds with the electrons in neighboring carbon atoms. This gives graphene its signature hexagonal shape. The fourth electron in each carbon atom, now known to be fermions, behave like relativistic particles described by the Dirac equation (which, in another sci-fi twist, also implies the existence of antimatter).

Getting back to graphene, it is those free electrons, in conjunction with the material's relative uniformity, that make graphene such an excellent electrical and thermal conductor, superior to copper and silver respectively. The strong covalent bonds between the carbon atoms, meanwhile, give graphene its strength.

Layers of graphene are bonded by weak van der Waals forces (the sum of attractive forces between two surfaces, accounting for a lizard's ability to climb vertical walls, among other things). The bonds between the carbon atoms in each layer of graphene, on the other hand, are incredibly strong; in fact, a hammock fabricated from a single-atom-thick sheet of graphene could support a load of nearly 9 pounds.

High-quality graphene is also lightweight, flexible, impermeable to other elements, and it's virtually transparent. Thanks to the space between its atoms, the material absorbs just 2.3 percent of white light, allowing 97 percent to pass through.

How graphene might be used

Potential applications for graphene are nearly limitless. Numerous projects are already underway in industries ranging from consumer electronics to sporting goods. To date, graphene-based consumer products have been limited to items that use a small amount of the substance in protective coatings. Once the mysteries of graphene manufacturing have been unlocked--more on that later--you can expect to find the material everywhere.

 

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