Heat Dissipation of Resonant Absorption in Metal Nanoparticle-Polymer Films Described at Particle Separation Near Resonant Wavelength

Jeremy R Dunklin,D Keith Roper

doi:10.1155/2017/2753934

Jeremy R Dunklin, D Keith Roper

Open Access

https://doi.org/10.1155/2017/2753934

Copy DOI

Abstract

Polymer films containing plasmonic nanostructures are of increasing interest for development of responsive energy, sensing, and therapeutic systems. The present work evaluates heat dissipated from power absorbed by resonant gold (Au) nanoparticles (NP) with negligible Rayleigh scattering cross sections randomly dispersed in polydimethylsiloxane (PDMS) films. Finite element analysis (FEA) of heat transport was coordinated with characterization of resonant absorption by Mie theory and coupled dipole approximation (CDA). At AuNP particle separation greater than resonant wavelength, correspondence was observed between measured and CDA-predicted optical absorption and FEA-derived power dissipation. At AuNP particle separation less than resonant wavelength, measured extinction increased relative to predicted values, while FEA-derived power dissipation remained comparable to CDA-predicted power absorption before lagging observed extinguished power at higher AuNP content and resulting particle separation. Effects of isolated particles, for example, scattering, and particle-particle interactions, for example, multiple scattering, aggregation on observed optothermal activity were evaluated. These complementary approaches to distinguish contributions to resonant heat dissipation from isolated particle absorption and interparticle interactions support design and adaptive control of thermoplasmonic materials for a variety of implementations.

Highlights

Thermal damping of resonant nanoparticles (NPs) dispersed in optically transparent polymer could affect potential implementations in biomedical therapeutics [1, 2], solar cells [3,4,5,6], optical interconnects [7,8,9], sensing [10,11,12], and chemical separation [13]
Measured optical responses of AuNP-PDMS films increased with NP concentration consistent with Mie and coupled dipole approximation (CDA) results at low concentrations
These results indicate scattering from isolated particles appears is unlikely from PDMS films containing 16 nm AuNP

Summary

Introduction

Thermal damping of resonant nanoparticles (NPs) dispersed in optically transparent polymer could affect potential implementations in biomedical therapeutics [1, 2], solar cells [3,4,5,6], optical interconnects [7,8,9], sensing [10,11,12], and chemical separation [13]. Optical damping by subwavelength Mie scatterers [14] in the Rayleigh regime [15] whose scattering cross sections are negligible [16] is due to absorption [17]. Resonant power absorption of isolated nanoparticles [16] and colloid suspensions [18] in homogeneous dielectric environments is describable using Beer-Lambert linearization [19, 20] of Mie theory. Interference to forward scattering, for example, reflection, refraction, or diffraction, due to an obstacle, [23] dielectric interface [24], applied field [25, 26], or other heterogeneity, may impact optical extinction [27,28,29], thermal dynamics [30], and temperature dispersion [31,32,33]. Evaluation of heat dissipated from power absorbed in nanocomposites to distinguish contributions from isolated scatterers, interacting scatterers, and heterogeneity is important to advance understanding and guide design of thermally responsive nanocomposite materials

Methods

Results

Conclusion