![]() They also found that 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 researchers found that the new material’s elastic modulus - a measure of how much force it takes to deform a material - is between four and six times greater than that of bulletproof glass. “With this advance, we have planar molecules that are going to be much easier to fashion into a very strong, but extremely thin material,” Strano says. The researchers showed that they could coat surfaces with films of the material, which they call 2DPA-1. “This mechanism happens spontaneously in solution, and after we synthesize the material, we can easily spin-coat thin films that are extraordinarily strong.”īecause the material self-assembles in solution, it can be made in large quantities by simply increasing the quantity of the starting materials. “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,” Strano says. ![]() These disks stack on top of each other, held together by hydrogen bonds between the layers, which make the structure very stable and strong. Under the right conditions, these monomers can grow in two dimensions, forming disks. ![]() For the monomer building blocks, they use a compound called melamine, which contains a ring of carbon and nitrogen atoms. However, in the new study, Strano and his colleagues came up with a new polymerization process that allows them to generate a two-dimensional sheet called a polyaramide. One reason for this was that if just one monomer rotates up or down, out of the plane of the growing sheet, the material will begin expanding in three dimensions and the sheet-like structure will be lost. However, many decades of work in this field led to the conclusion that it was impossible to create such sheets. ![]() Polymer scientists have long hypothesized that if polymers could be induced to grow into a two-dimensional sheet, they should form extremely strong, lightweight materials. Once formed, polymers can be shaped into three-dimensional objects, such as water bottles, using injection molding. These chains grow by adding new molecules onto their ends. Polymers, which include all plastics, consist of chains of building blocks called monomers. Credit: polymer film courtesy of the researchers Christine Daniloff, MIT Two dimensions ![]() The new material is a two-dimensional polymer that self-assembles into sheets and could be used as a lightweight, durable coating for car parts or cell phones, or as a building material for bridges or other structures. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |