High-concentration, surfactant-stabilized graphene dispersions.

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Liquid-phase processing of graphene is crucial for its scalable applications.
• Achieving high concentrations of stable graphene dispersions remains a challenge.

Purpose of the Study:

• To present a method for producing stable, high-concentration graphene dispersions in water.
• To characterize the properties of graphene flakes produced by this method.
• To evaluate the scalability and potential applications of the produced dispersions.

Main Methods:

• Graphene oxide was dispersed in water with sodium cholate surfactant.
• Low power sonication was applied for extended periods (up to 400 hours).
• Centrifugation was used to isolate and purify the graphene dispersions.

Main Results:

• Stable graphene dispersions were achieved at concentrations up to 0.3 mg/mL.
• Graphene flakes consisted of 1-10 stacked monolayers, with an average of 4.
• Flake dimensions (approx. 1 µm length, 400 nm width) were stable, with minimal defects for centrifugation rates below 2000 rpm.
• Dispersions could be cast into high-quality free-standing films.

Conclusions:

• The developed method offers a scalable approach for liquid-phase processing of graphene.
• The resulting graphene dispersions are suitable for fabricating high-quality films.
• This technique broadens the scope for graphene utilization in diverse technological applications.