Clipped from: New Plastic Conducts Heat Better Than Metals, But Only in One Direction | Popular Science |
New Plastic Conducts Heat Better Than Metals, But Only in One Direction
Polyethylene Chains of polyethylene molecules like the one above tend to arrange themselves chaotically, but by figuring out how to make the molecules line up straight, MIT researchers have created a highly conductive new polymer that conducts heat in only one direction.
Clipped from: MIT NanoEngineering Group |
The Nanoengineering Group is part of the Mechanical Engineering Department at MIT. Our research is focused on nanoscale energy transport, conversion, and storage. There are fundamental differences between transport processes at the nanoscale and the macroscale due to quantum and classical size effects; for example, both classical diffusion laws and Planck's law for blackbody radiation break down in nanostructures.
Clipped from: NanoEngineering: News |
MIT News: Insulators made into conductors
Sheng Shen, Asegun Henry, Jonathan Tong, Ruiting Zheng, and Professor Gang Chen have shown that polymers can be as good conductors as many metals. Their letter, published March 7 in Nature Nanotechnology, describes how drawing polymer fibers causes molecular chain alignment. This alignment leads to the anisotropically high thermal conductivity while maintaining low electrical conductivity. Materials with such properties could be used to solve many thermal management problems. Read the full article in MIT News.
Clipped from: Insulators made into conductors |
The new method involves pulling a thin thread of material (top) from a liquid solution (bottom), and in the process the individual polymer filaments, which start out as a tangled mass, become very highly aligned.
At top, an illustration of the tangled nature of the polymer filaments, with heat-stopping voids indicated as dark blobs. When drawn and heated into a thin thread (bottom), the molecules line up and the voids are compressed, making the material a good conductor.
Clipped from: MIT MechE - Gang Chen |
Sources:
- New Plastic Conducts Heat Better Than Metals, But Only in One Direction | Popular Science
- MIT NanoEngineering Group
- NanoEngineering: News
- Insulators made into conductors
- MIT MechE - Gang Chen