Ripening kinetics of bubbles: A molecular dynamics study.

Area of Science:

• Materials Science
• Chemical Engineering
• Physics

Background:

• Bubble coarsening is a critical phenomenon in multiphase systems.
• Understanding the kinetics of bubble ripening is essential for various industrial processes.

Purpose of the Study:

• To investigate the temperature and gas volume fraction dependence of bubble ripening kinetics.
• To validate the applicability of Lifshitz-Slyozov-Wagner (LSW) theory under different conditions.

Main Methods:

• Molecular dynamics simulations were employed to model bubble systems.
• Time evolution of bubble growth rates was analyzed to determine ripening kinetics.

Main Results:

• At low temperatures, bubble growth followed a t^1/2 law, consistent with reaction-limited coarsening predicted by LSW theory.
• At high temperatures, a t^1/3 law suggested diffusion-limited coarsening, but accuracy was insufficient for full LSW validation.
• Low-temperature coarsening showed minimal gas volume fraction sensitivity up to 10%.

Conclusions:

• Bubble coarsening is reaction-limited at low temperatures, validating LSW theory.
• At high temperatures, diffusion-limited coarsening deviates from LSW theory with increasing gas volume fraction.
• Mean-field approximations are valid for reaction-limited systems but not for diffusion-limited systems at higher concentrations.