Gold Nanoparticles Allow Optoplasmonic Evaporation from Open Silica Cells with a Logarithmic Approach to Steady-State Thermal Profiles

• Published in: Journal of physical chemistry. C Vol. 114; no. 22; pp. 10132 - 10139
• Main Authors: Russell, Aaron G, McKnight, Matthew D, Sharp, Adam C, Hestekin, Jamie A, Roper, D. Keith
• Format: Journal Article
• Language: English
• Published: American Chemical Society 10.06.2010
• Subjects: C: Nanops and Nanostructures
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp101762n

In this work, plasmonically heated solid-state gold nanoparticle (AuNP) arrays are investigated under novel conditions that include large (>35 °C) steady-state (SS) temperature increases (ΔT) dominated by conduction in open environments that allow vapor−liquid phase change. Evaporative cooling from the open system decreases SS ΔT of the system by as much as (11.6 ± 0.33) °C (45%), consistent with predictions from an energy balance model expanded in this work to account for evaporative cooling and associated decreasing thermal mass. Comparing dynamic and steady temperature profiles from water evaporating from a AuNP-coated Si cell at 50 mW laser irradiation with the model yielded an average accumulated residual sum of squares of 2.95 °C2 over 200 s. Temperature increases that distribute nonuniformly across sample cell surfaces due to high laser power (≤150 mW) and conductive heat transfer are accurately and uniformly (<0.7% difference) represented by an infinite fin model at laser powers from 50 to 150 mW, resulting in R 2 values near unity. Overall heat transfer coefficients for air cells estimated from both dynamic and steady-state models agree within 2.05 to 11.45%. This model independence allows predicting temporal evolution or steady-state distribution of temperatures from just two measured values. The improved models and increased understanding of these systems will play an important role in implementing plasmonically heated structures in sustainable energy applications, biomedical applications and many others.