Nanoscale Wetting and Energy Transmission at Solid/Liquid Interfaces

Understanding the
effects and limitations of solid/liquid interfaces
on energy transport is crucial to applications ranging from nanoscale
thermal engineering to chemical synthesis. Until now, the majority
of experimental evidence regarding solid/liquid interactions has been
limited to macroscale observations and experiments. The lack of experimental
works exploring nanoscale solid/liquid interactions has been accentuated
as the body of knowledge from theory and simulations at these scales
has exploded in recent years. In this study, we expand on current
nanoscale thermal measurement techniques in order to more fully understand
solid/liquid interfacial energy transport. We use thermal ablation
threshold measurements on thick Au films in various liquids as a metric
to describe thermal transport at the Au/liquid interface. Furthermore,
using ultrafast pump–probe experiments, we gain insight into
this transport through picosecond ultrasonic coupling at solid/liquid
interfaces with known macroscopic observations. We find significant
variations in both the ablation threshold and the damping of the acoustic
modes within the Au films depending on nanoscopic interactions at
the solid/liquid interface rather than typical macroscale metrics
such as acoustic mismatch, measured contact angle, and work of adhesion.