Tailoring Nanofluid Thermophysical Profile through Graphene Nanoplatelets Surface Functionalization

Area of Science:

• Materials Science
• Nanotechnology
• Fluid Dynamics

Background:

• Graphite nanoplatelets (GNPs) are utilized in nanofluids for enhanced properties.
• Surface functionalization is a key method to tailor nanoparticle behavior.
• Understanding transport properties is crucial for nanofluid applications.

Purpose of the Study:

• To investigate the impact of chemical surface functionalization via oxidation on the transport properties of exfoliated graphite nanoplatelets in aqueous nanofluids.
• To analyze changes in thermal conductivity and viscoelasticity after GNP oxidation.
• To establish nanostructure surface functionalization as a tunable strategy for nanofluid thermophysical properties.

Main Methods:

• Exfoliation of graphite to produce nanoplatelets.
• Chemical surface functionalization of nanoplatelets through oxidation.
• Determination of thermal conductivity of the resulting nanofluids.
• Measurement of viscoelastic properties (viscosity, yield stress, storage and loss moduli) of the nanofluids.

Main Results:

• Oxidation of exfoliated graphite nanoplatelets drastically altered the internal structure of the aqueous suspension.
• Significant, orders-of-magnitude shifts were observed in viscosity, yield stress, storage modulus, and loss modulus.
• The functionalization also demonstrably influenced the thermal conduction properties of the nanofluids.
• A direct correlation between structural changes and thermophysical property modifications was established.

Conclusions:

• Chemical surface functionalization, specifically oxidation, is an effective method to tune the thermophysical properties of graphite nanoplatelet-based nanofluids.
• Altering the surface chemistry of nanoplatelets provides a powerful strategy for controlling nanofluid behavior.
• This approach offers potential for designing advanced nanofluids with tailored thermal and rheological characteristics.