Direct insight into the three-dimensional internal morphology of solid-liquid-vapor interfaces at microscale

Area of Science:

• Surface science
• Materials science
• Physics

Background:

• Solid-liquid-vapor interfaces, particularly the three-phase contact line, are crucial active centers in biological and industrial reactions.
• Understanding the morphology of these interfaces is essential for optimizing processes and developing new technologies.

Purpose of the Study:

• To provide direct 3D experimental evidence of the internal morphology of interfaces in Cassie or Wenzel states.
• To quantitatively visualize the internal 3D fine structures and phases within intact samples.
• To investigate liquid distribution on superhydrophobic surfaces in the Cassie regime.

Main Methods:

• Utilized X-ray micro-computed tomography (X-ray micro-CT) for high-resolution 3D imaging.
• Applied micron-level resolution to observe internal morphological structures.
• Analyzed intact samples to visualize internal phases and fine structures.

Main Results:

• Direct 3D visualization of internal interface morphology in Cassie and Wenzel states was achieved.
• Liquid was observed to be randomly and partly located on protrusions in the Cassie regime on superhydrophobic surfaces.
• This liquid distribution results from thermodynamically optimal minimization of surface energy.

Conclusions:

• The findings offer new insights into the behavior of liquid on superhydrophobic surfaces.
• The study aids in optimizing classical wetting theories and models.
• This research promotes advancements in surface science and technology.