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

By embedding metal nanoparticles within polymeric materials, selective thermal polymer processing can be accomplished via irradiation with light resonant with the nanoparticle surface plasmon resonance due to the photothermal effect of the nanoparticles which effi ciently transforms light into heat. The wavelength and polarization sensitivity of photothermal heating from embedded gold nanorods is used to selectively process a collection of polymeric nanofi bers, completely melting those fi bers lying along a chosen direction while leaving the remaining material largely unheated and unaffected. Fluorescence-based temperature and viscosity sensing was employed to confi rm the presence of heating and melting in selected fi bers and its absence in counter-aligned fi bers. Such tunable specifi city in processing a subset of a sample, while the remainder is unchanged, cannot easily be achieved through conventional heating techniques.