Vapor-liquid equilibrium in electric field gradients

Area of Science:

• Thermodynamics and Statistical Mechanics
• Fluid Dynamics
• Physical Chemistry

Background:

• Vapor-liquid coexistence is fundamental to many physical processes.
• Electric fields can influence fluid behavior, but their effect on phase transitions is complex.
• Nonuniform electric fields introduce unique challenges in modeling fluid interfaces.

Purpose of the Study:

• To investigate vapor-liquid coexistence in polar and nonpolar fluids under nonuniform electric fields.
• To determine the influence of electric fields on surface tension and phase diagrams.
• To explore the nucleation of bubbles and droplets induced by electric fields.

Main Methods:

• Utilizing squared-gradient theory to model the vapor-liquid interface.
• Analyzing the effects of controlled surface potential (charge) on surface tension.
• Examining the dependence of phase diagram alterations on dielectric constant constitutive relations.

Main Results:

• A sufficiently strong electric field can induce nucleation of gas bubbles from liquid or liquid droplets from vapor.
• Surface tension is modified by the electric field: increasing with surface potential and decreasing with surface charge.
• The impact of electric fields on fluid phase diagrams is highly sensitive to the dielectric properties of the fluid.
• Electric-field-induced nucleation can occur away from container surfaces.

Conclusions:

• Nonuniform electric fields provide a novel mechanism for controlling phase transitions in fluids.
• The study quantifies the relationship between electric field strength, fluid properties, and interfacial phenomena.
• Findings have implications for understanding and manipulating fluid behavior in diverse applications, from materials science to microfluidics.