Soret-decoupled thermoelectric potential in binary highly ionized liquids.

Area of Science:

• Physical Chemistry
• Thermodynamics
• Materials Science

Background:

• The Seebeck effect describes the conversion of temperature differences into electric voltage.
• Understanding this effect in ionized fluids is crucial for thermoelectric applications.
• Previous models often rely on kinetic parameters, limiting their applicability.

Purpose of the Study:

• To develop a self-consistent theory for the Seebeck effect in highly ionized fluids.
• To express the Seebeck coefficient using fundamental thermodynamic properties like molecular entropy.
• To explain observed Seebeck coefficients in modified polymer solutions.

Main Methods:

• Utilizing nonequilibrium thermodynamics and Onsager kinetic coefficients.
• Deriving material transport equations from thermodynamic fluxes.
• Calculating the heat of transport as a quasi-equilibrium parameter.

Main Results:

• A novel thermodynamic model for the Seebeck effect was established.
• The Seebeck coefficient is expressed through component molecular entropies, independent of kinetic factors.
• The model successfully explains large Seebeck coefficients in NaOH-modified polyethylene glycol (PEG) solutions.

Conclusions:

• The developed theory provides a robust framework for understanding the Seebeck effect in ionized fluids.
• Increased ion-based molecular entropy is identified as the cause for large Seebeck coefficients in PEG solutions.
• The model's predictions align with experimental data, validating its thermodynamic approach.