Since the realization of the electrical conductivity in conjugated polymers during the late
seventies, this class of organic materials has received growing attention due to their
technological applications. In addition to their attractive processing properties associated
with conventional polymers, conjugated polymers have both electrical and optical properties
similar to those of metals and inorganic semiconductors. Similar to traditional
non-conjugated polymers, conjugated polymers possess a very low intrinsic thermal
conductivity (~ 0.2 W m-1 K-1). Defects in bulk polymers such as chain entanglements,
voids, and impurities lead to a significant number of phonon scattering sites that impede
heat transfer. The utility of these polymers as thermal interface materials depends largely
on (i) the directional carrier mobility through the polymer chain (ii) the contact area and
resistance between polymer and surfaces. Further, the alignment of polymer chains with
enhanced molecular and superamolecular order at the nanoscale can reduce defects and
improve the mechanical strength and thermal/electrical conductivity in the direction of
alignment significantly. This presentation will cover the template assisted fabrication of
conjugated polymer (polythiophene) nanostructures towards enhanced molecular ordering
within nanostructures. The polythiophene (Pth) nanostructures of diameters ~ 200 nm and
length up to tens of micron were grown potentiostatically using a three electrode
electrochemical cell and a hard nanoporous template. The important fabrication parameters
to control the morphology of nanostructures will also be discussed. A photoacoustic (PA)
technique was used to measure the thermal resistances of Pth nanotube arrays dry-adhered
to a substrate to form the interface. The total thermal resistance of a Pth nanotube
interface was measured to be as low as ~ 1 mm2K/W, which is significantly less than the measured resistances for state of art thermal adhesives.
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