Anisotropic Thermal Processing of Polymer Nanocomposites via the Photothermal Effect of Gold Nanorods*

Embedding metal nanoparticles within polymeric materials enables spatially-selective, in-situ thermal polymer processing [1,2]. When irradiating such a nanocomposite with light resonant with the particle's surface plasmon resonance, the photothermal effect efficiently transforms the energy into localized heat. Utilizing anisotropically-shaped particles enables further heating control based on the polarization sensitivity of the light-particle interaction. Photothermal heating from oriented gold nanorods selectively heats polymeric nanofibers by melting fibers lying only along a chosen direction while leaving the remaining material largely unaffected [3]. Fluorescence-based temperature-sensing measurements confirms heating in selected fibers and its absence in counter-aligned fibers. Such facile thermal processing of a specified subset of a sample, while the remainder is unchanged cannot be achieved through conventional heating. Results on spatially-selective heating and nanoscale temperature measurements within polymer systems doped with active nanoparticles will be discussed.\\[4pt] [1] S. Maity et al., \textit{Polymer} \textbf{52}, 1674 (2011).\\[0pt] [2] S. Maity et al., \textit{Adv. Funct. Mat.} (in press) (2012).\\[0pt] [3] S. Maity et al., \textit{Part. \& Part. Syst. Char.} (in press) (2012).