Tuning the electrical conductivity of exfoliated graphite nanosheets nanofluids by surface functionalization

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Exfoliated graphite is a promising material for various applications.
• Understanding the electrical properties of graphite-based nanofluids is crucial for their technological development.
• Oxidation is a common surface modification technique that can alter material properties.

Purpose of the Study:

• To experimentally determine the electrical conductivity of exfoliated graphite in water nanofluids.
• To investigate the effect of oxidation on the electrical conductivity of these nanofluids.
• To compare the conductivity behavior of nanofluids with sintered dry graphite.

Main Methods:

• Preparation of exfoliated graphite water nanofluids.
• Experimental determination of electrical conductivity.
• Oxidation of exfoliated graphite nanosheets.
• Comparison of conductivity in raw and oxidized nanofluids, and with sintered graphite.

Main Results:

• Electrical conductivity of exfoliated graphite nanofluids was measured.
• Oxidation altered the electrical conductivity, with different effects compared to sintered graphite.
• Sintered graphite exhibited metallic conduction, while nanofluids showed weak electrolyte behavior.
• Oxidation's effect is attributed to the dissociation of functional groups in the fluid phase.

Conclusions:

• Oxidation significantly modifies the electrical conductivity of exfoliated graphite nanofluids.
• The observed changes are linked to chemical functionalization and dissociation in the fluid.
• This research opens avenues for designing functionalization processes to control nanofluid conductivity.