Graphene is a special material made of a single layer of carbon atoms. It is incredibly strong, even 200 times stronger than steel, but very light, even lighter than paper. It also has excellent electrical and mechanical properties. However, recent research from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory has shown that it has some limitations.
The scientists looked at a type of graphene called polycrystalline graphene, which is made using a process called chemical vapor deposition and has tiny defects in its structure. They studied its toughness, which means how well it can resist breaking. While polycrystalline graphene is very strong, it was found to have relatively low toughness – lower than diamond and just a bit higher than pure graphite.
Toughness is essential for materials used in important structures, like nuclear reactor pressure vessels. Being strong alone is not enough; a material also needs to be able to withstand cracks and fractures. The researchers made a mathematical model to better understand and predict how polycrystalline graphene behaves when it breaks.
For critical structures, engineers need materials that are both strong and tough. Strength is about resisting changes in shape, and toughness is about resisting breaks and fractures.
While very strong materials, like super-strong steels, can be used for specific purposes, they can be risky for critical structures because they might fail suddenly and completely. So, materials with high toughness are preferred to make sure structures are safe and reliable.
