We all know polymers or plastics are very good insulators for both electricity and heat. Plastics are known to have thermal conductivities on the order of 0.1 Wm-1 K-1. It is about time to change that understanding.
Prof. Chen's group at MIT has shown that polyethylene (PE), a commodity thermoplastic could be made highly conductive. The group fabricated high quality ultra-drawn PE nanofibers having diameter of 50 to 500 nm and lengths up to 10 mm and realized that thermal conductivity has increased to ~ 104 Wm-1 K-1. This value is the highest thermal conductivity seen in any polymer. The group attributed this attractive property to restructuring of polymer chains by stretching. However, this drawing process makes the plastic conduct heat very efficiently in just one direction while metals conduct heat in all directions. Perhaps that is why this work is creating a buzz in the scientific community. Now, one could use these ultradrawn nanofibers for applications to draw heat away from an object such as a computer processor chips, solar heat collectors or heat exchangers.
The main question is: could this invention be made cost effective to commercialize plastics with high thermal conductivity?
[Reference: S. Shen, A. henry, J. Tong, R. Zheng, and G. Chen; Nature Nanotechnology; doi:10.1038/nnano.2010.27 Published online: March 7, 2010]
