Thermophysical properties of interfacial layer in nanofluids.

Area of Science:

• Materials Science
• Colloidal Science
• Thermodynamics

Background:

• Nanofluids exhibit higher thermal conductivity than base fluids, but the underlying mechanisms remain unclear.
• Brownian motion is a proposed mechanism, but it doesn't fully account for observed thermal enhancements.
• Surface-charge-induced electrical double layers play a role in nanofluid behavior.

Purpose of the Study:

• To propose and validate a new conceptual model for nanofluid thermal conductivity.
• To investigate the role of an interfacial layer in enhancing thermal transport.
• To develop explicit equations for the interfacial layer's properties.

Main Methods:

• Applied principles of colloidal science to model the interfacial layer.
• Developed a fractal model incorporating the interfacial layer concept.
• Compared model predictions with experimental data for CuO-water nanofluids.

Main Results:

• Derived explicit equations for the thickness and thermal conductivity of the interfacial layer.
• The fractal model accurately predicted experimental results.
• Demonstrated the influence of pH, temperature, volume fraction, and particle size on nanofluid performance.

Conclusions:

• The proposed interfacial layer is a key factor in nanofluid thermal conductivity.
• The developed fractal model provides a robust framework for understanding nanofluid behavior.
• This research offers a more comprehensive explanation for the superior thermal properties of nanofluids.