Controlled Sonication as a Route to in-situ Graphene Flake Size Control

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Ultrasonication is a common method for exfoliating two-dimensional (2D) van der Waals layered materials like graphene.
• The underlying mechanism, inertial cavitation, is not well understood, leading to inefficient exfoliation processes.
• Current methods often result in low yields, poor material quality, and broad flake size distributions, limiting economic feasibility.

Purpose of the Study:

• To investigate and optimize the role of inertial cavitation in graphene exfoliation.
• To establish a correlation between inertial cavitation dose and graphene yield, flake size, and exfoliation rate.
• To enhance the economic viability of producing 2D materials through controlled ultrasonication.

Main Methods:

• Controlled ultrasonication of graphene in an aqueous medium.
• Measurement and optimization of inertial cavitation dose.
• Analysis of few-layer graphene yield and flake size distribution.
• Correlation studies between cavitation dose and exfoliation parameters.

Main Results:

• Achieved few-layer graphene yields up to 18% within three hours by optimizing inertial cavitation dose.
• Demonstrated that inertial cavitation preferentially exfoliates larger graphene flakes.
• Established a strong correlation between inertial cavitation dose and graphene exfoliation rate and flake dimensions.
• Observed a decrease in exfoliation rate over time due to preferential exfoliation of larger flakes.

Conclusions:

• Measurement and control of inertial cavitation are critical for optimizing high-yield, size-selected exfoliation of nanomaterials.
• Optimized inertial cavitation offers a pathway to economically viable production of 2D van der Waals layered materials.
• This method holds potential for high-volume flow cell production of 2D nanomaterials.