Bulk and localized plasmonic heating in nanogold doped polymers

Abstract

Colloidal gold (Auc) nanoparticles (GNPs) and nanorods (GNRs) were incorporated into polymer blend films and electrospun fibers to utilize the nanoparticle plasmonic response for localized heating of the polymer. In this work, mathematical modeling was used to describe the GNP distribution and heat/melt profile surrounding each GNP in the polymer blend, demonstrating that a bulk temperature change of only 0.2 °C results in a 20-nm-diameter melted polymer sphere around the GNP. In addition, it was shown that by reducing the radius of polymer material around the GNP through the use of electrospinning fibers in place of thin film deposition, heating of the bulk material increased by 72%. Bulk heating of polymer blend films containing either GNPs or GNRs was mapped using an infrared camera system with light-emitting diodes (LEDs) at 530 and 810 nm. The change in temperature observed in the thin films was used to calculate the photothermal energy conversion efficiency of the respective nanogold doped polymer thin films. Significantly, GNR-doped film efficiencies recorded were up to 6.6 times (558.6% increase) that of the polymer blend-only film when interrogated at 810 nm, while the GNP-doped film efficiency increased by 1.8 times (75.7% increase) under the 530 nm LED.