Polymers, such as plastics, are made up of chains of units called monomers. Although these chains are one-dimensional, they can be shaped into three-dimensional objects through manufacturing methods like injection molding.
With that said, polymer scientists have long tried to grow polymers into two-dimensional (2D) sheets in a bid to create extremely strong and lightweight materials. While some have successfully achieved that feat, their resulting materials had faults, which reduced their strength and other desirable features.
Now, scientists at MIT have finally overcome that barrier with the help of a new production method that can create 2D sheets while maintaining the material’s strength, reports New Atlas.
As part of their study, published in Nature, the researchers used melamine as the monomer, which is made up of carbon and nitrogen rings. Under the right conditions, this monomer starts growing sideways, forming 2D disk shapes. These disks then stack on top of each other, held together by hydrogen bonds, giving the material its impressive strength.
“Instead of making a spaghetti-like molecule, we can make a sheet-like molecular plane, where we get molecules to hook themselves together in two dimensions,” said Michael Strano, senior author of the study. “This mechanism happens spontaneously in solution, and after we synthesize the material, we can easily spin-coat thin films that are extraordinarily strong.”
The team found that although the material — called 2DPA-1 — is extremely thin and lightweight, it is two times stronger than steel and about six times more durable than bulletproof glass. Additionally, the material is impermeable to gasses and liquids.
Boasting these abilities, the material could potentially be used to create ultra-thin coatings for vehicles and electronic devices like smartphones, as well as find applications as a construction material for bridges. “This kind of barrier coating could be used to protect metal in cars and other vehicles, or steel structures,” said Strano.
Source study: Nature – Irreversible synthesis of an ultrastrong two-dimensional polymeric material
