Reversible Stacking and Delamination-Regulation of MXene via Controlled Freezing

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• MXene material configuration (aggregated vs. dispersed) critically impacts its properties and applications.
• Controlling MXene's structure, such as aggregation and delamination, remains a significant challenge in materials science.

Purpose of the Study:

• To develop a simple, scalable, and reversible strategy for controlling MXene configuration.
• To investigate the effects of controlled freezing on MXene aggregation, delamination, and interlayer spacing.

Main Methods:

• Utilizing controlled freezing of aqueous MXene dispersions as the primary method.
• Analyzing the influence of freezing parameters on ice crystal formation and its interaction with MXene.
• Characterizing the aggregation percentage, delamination percentage, and interlayer spacing of MXene aggregates.

Main Results:

• A novel, additive-free, and reaction-free method to optionally and reversibly regulate MXene aggregates (AM).
• Fine-tuning of AM aggregation, delamination, and interlayer spacing achieved solely through controlled freezing.
• Established the mechanism: freezing-induced ice grain squeezing causes aggregation, while ice formation between lamellae causes delamination.

Conclusions:

• Controlled freezing provides a green and effective approach for manipulating MXene's assembly structure.
• This method offers significant potential for the preparation, storage, and diverse applications of MXene materials.
• Opens new avenues for controlling material structures through environmentally friendly physical processes.