Effect of liquid temperature on sonoluminescence

Area of Science:

• Acoustics
• Physical Chemistry
• Plasma Physics

Background:

• Sonoluminescence (SL) is the emission of light from collapsing bubbles in a liquid under acoustic irradiation.
• The physical mechanisms underlying SL, including plasma emission and chemiluminescence, are complex and depend on various parameters.
• Understanding the influence of liquid temperature on SL is crucial for optimizing light emission and elucidating underlying processes.

Purpose of the Study:

• To investigate the effect of liquid temperature on bubble oscillations and sonoluminescence emissions in water using computer simulations.
• To differentiate the temperature dependence of plasma emissions and OH chemiluminescence in single-bubble sonoluminescence (SBSL).
• To explain the observed liquid-temperature dependence of multibubble sonoluminescence (MBSL) in water.

Main Methods:

• Computer simulations of bubble oscillations under sonoluminescence conditions in water at various liquid temperatures.
• Analysis of bubble temperature at collapse, trapped water vapor content, and saturated vapor pressure.
• Modeling of plasma emissions and OH radical chemiluminescence intensity as a function of acoustic amplitude and liquid temperature.

Main Results:

• Colder liquids lead to higher bubble collapse temperatures due to reduced trapped water vapor.
• At low acoustic amplitudes, SL plasma emissions are stronger in colder liquids.
• At high acoustic amplitudes, OH chemiluminescence is weaker in colder liquids due to reduced excited OH radical formation.

Conclusions:

• The liquid temperature significantly impacts the dominant emission mechanism in sonoluminescence.
• Multibubble sonoluminescence (MBSL) is generally stronger in colder liquids because plasma emissions, favored by lower temperatures, dominate.
• The study provides insights into the temperature-dependent nature of SBSL and MBSL, crucial for controlling and understanding these phenomena.