title: Study of Heat Transfer Dynamics from Gold Nanorods to the Environment via Time-Resolved Infrared Spectroscopy.
abstract: Studying the local solvent surrounding nanoparticles is important to understanding the energy exchange dynamics between the particles and their environment, and there is a need for spectroscopic methods that can dynamically probe the solvent region that is in nearby contact with the nanoparticles. In this work, we demonstrate the use of time-resolved infrared spectroscopy to track changes in a vibrational mode of local water on the time scale of hundreds of picoseconds, revealing the dynamics of heat transfer from gold nanorods to the local water environment. We applied this probe to a prototypical plasmonic photothermal system consisting of organic CTAB bilayer capped gold nanorods, as well as gold nanorods coated with varying thicknesses of inorganic mesoporous-silica. The heat transfer time constant of CTAB capped gold nanorods is about 350 ps and becomes faster with higher laser excitation power, eventually generating bubbles due to superheating in the local solvent. Silica coating of the nanorods slows down the heat transfer and suppresses the formation of superheated bubbles.
authors: Institute of Physical Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany.
authors: Son C
authors: SC
authors: Nguyen
authors: Qiao
authors: Q
authors: Zhang
authors: Karthish
authors: K
authors: Manthiram
authors: Xingchen
authors: X
authors: Ye
authors: Justin P
authors: JP
authors: Lomont
authors: Charles B
authors: CB
authors: Harris
authors: Institute of Physical Chemistry, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany.|Department of Chemistry, Faculty of Science, King Abdulaziz University , Jeddah 21589, Saudi Arabia.
authors: Horst
authors: H
authors: Weller
authors: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|The Hamburg Centre for Ultrafast Imaging, University of Hamburg , Luruper Chaussee 149, 22761 Hamburg, Germany.
authors: A Paul
authors: AP
authors: Alivisatos
keywords: electron ejection; heat transfer; plasmonic nanoparticle; silica coating; time-resolved infrared spectroscopy