Ultra-fine fibers designed with exceptional strength

A new technology developed at the Massachusetts Institute of Technology has the potential to create strong, resilient nanofibers for many applications.

Researchers have developed a method that can produce ultra-thin fibers – measured in nanometers in diameter – characterized as exceptionally strong and tough. These fibers, which are supposed to be inexpensive and easy to make, can be used to make a variety of products, including protective armor and nanocomposites.

The new process, called gel electrospinning, was developed by technologists led by Gregory Rutledge, a professor at the Massachusetts Institute of Technology. The inventors explain, “There are many trade-offs. Usually, when engineers try to improve one characteristic of a material, they see a decrease in another characteristic. ” Routledge’s refinements have resulted in ultra-thin polyethylene fibers that equal or exceed the properties of some of the toughest polymers and fibrous materials such as Kevlar and Dynema.

“We started by making fibers in a different range of sizes, namely below 1 micron, because they have many interesting functions.” High performance fibers, which include aramids such as Kevlar, and gelled polyesters such as Dyneema and Spectra, are used in extreme rope applications and as reinforcement fibers in some high performance composites.

“There has been little new in this area in recent years,” says Rutledge. But this new material, he said, is superior to existing ones. Compared to carbon fibers and ceramic fibers, which are widely used in composite materials, the new polyethylene fibers obtained by gel electrospinning have the same strength, but are much stiffer and less dense. This means they are superior to standard materials.

By creating this ultra-thin polyethylene, MIT technologists tried to approach the properties of existing microfibers, but, in fact, the result was much better.

The new electrospinning gel fibers combine the desired properties of strength, stiffness and toughness.

The new process combines the use of polymer gel as in gel fibers, but uses electrical forces rather than mechanical tension to pull the fibers, resulting in ultra-fine dimensions resulting in unique filament properties. These results could result in protective materials being as strong as existing ones, but thinner and less heavy, making them more practical. So

urce: netcomposites.com