Thermal conductivity measurement of individual polythiophene nanofibers with suspended micro-resistance thermometer devices

High thermal conductivity, comparable to that of a metal, has been observed in some stretched polyethylene nanofibers due to a decrease in defect density with the alignment of the polymer chains. Such high thermal conductivity may be useful for thermal management applications such as thermal adhesives made of aligned nanofibers. Polythiophene (Pth) is a conducting polymer that can be synthesized electrochemically as aligned nanofiber forests without the need for stretching individual fibers. Here we report the thermal conductivity of individual suspended Pth nanofibers synthesized electrochemically and measured with the use of a microfabricated device in the temperature range of 80 K to 375 K. The measured thermal conductivity increases with temperature. For three single suspended Pth nanofibers with a diameter on the order of 200 nm, the room temperature value between 0.6 and 0.8 W/m K is about four-fold higher than that reported for Pth thin films and comparable to that reported for binder-filler thermal adhesives. Copyright © 2012 by ASME.