Wetting transition and phase separation on flat substrates and in porous structures

Area of Science:

• Physical Chemistry
• Materials Science
• Surface Science

Background:

• Wetting phenomena are crucial in various scientific and industrial applications.
• Understanding the behavior of immiscible fluids is complex and requires advanced simulation techniques.
• Cahn's wetting transition theory highlights the importance of surface composition in wetting processes.

Purpose of the Study:

• To investigate the wetting behavior of two-component immiscible fluids using numerical simulations.
• To analyze the energetic contributions (wall energy, surface excess energy) to wetting as a function of temperature.
• To elucidate the mechanisms of complete wetting and their implications for microstructural arrangements.

Main Methods:

• Numerical simulations of immiscible fluid wetting.
• Analysis of energetic contributions, including wall energy and surface excess energy.
• Investigation of wetting phenomena in both flat and porous substrates.

Main Results:

• Identified two distinct mechanisms for complete wetting: surface tension driven and diffusion induced.
• Demonstrated that surface composition, influenced by temperature, plays a vital role in wetting behavior.
• Observed unique wetting phenomena in porous structures compared to flat substrates, showcasing diverse microstructural arrangements.

Conclusions:

• The study provides an alternative interpretation for complete wetting, distinct from classic Young's law.
• The findings reveal novel mechanisms governing fluid behavior at interfaces.
• The research offers potential for designing advanced superhydrophilic structures with tailored properties.