A team of chemical engineers at the Massachusetts Institute of Technology (MIT) has created a new material stronger than steel and light as plastic, opening up potential applications in building as well as automotive and cell phone manufacturing as a protective coating.
Created using an innovative polymerisation process, the new material is a two-dimensional polymer that self-assembles into sheets, unlike all other polymers, which form one-dimensional, spaghetti-like chains. The material called 2DPA-1 can be easily manufactured in large quantities, and could find use as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges and other structures, says Michael Strano, the Carbon P. Dubbs Professor of Chemical Engineering at MIT and senior author of the new study.
“We don’t usually think of plastics as being something that you could use to support a building, but with this material, you can enable new things,” he said.
The new polymerisation process allows a two-dimensional sheet called a polyaramide to be generated. For the monomer building blocks, a compound called melamine, which contains a ring of carbon and nitrogen atoms, is used. Under the right conditions, these monomers can grow in two dimensions, forming disks, which stack on top of each other, held together by hydrogen bonds between the layers, which make the structure very stable and strong.
“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. This mechanism happens spontaneously in solution, and after we synthesise the material, we can easily spin-coat thin films that are extraordinarily strong,” Strano explained.
According to the researchers, the new material’s elastic modulus, which is a measure of how much force it takes to deform a material, is 4-6 times greater than that of bulletproof glass. Its yield strength, or how much force it takes to break the material, is twice that of steel, even though the material has only about one-sixth the density of steel.
The new material is also impermeable to gases unlike other polymers. “This could allow us to create ultrathin coatings that can completely prevent water or gases from getting through,” Strano said.
“This kind of barrier coating could be used to protect metal in cars and other vehicles, or steel structures.”
MIT News reports that the researchers have filed for two patents on the process they used to generate the material. The study has been published in Nature. MIT postdoc Yuwen Zeng is the lead author of the study.
Image: The material could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures (Image source: MIT)
