Measuring the Surface Energy of Nanosheets by Emulsion Inversion

Area of Science:

• Materials Science
• Colloid and Surface Chemistry
• Nanotechnology

Background:

• Solution-processed nanomaterials offer versatile assembly via interfacial techniques.
• Two-dimensional (2D) materials are promising for nanosheet-stabilized emulsions and surface energy studies.

Purpose of the Study:

• To demonstrate emulsions stabilized by 2D materials, specifically titanium carbide (Ti3C2Tx) MXene.
• To develop an in situ method for measuring nanosheet surface energy using emulsion inversion.
• To investigate the influence of pH and nanosheet size on the surface energy of various 2D materials.

Main Methods:

• Emulsion stabilization using 2D materials including MXene, graphene oxide, pristine graphene, and molybdenum disulfide.
• In situ measurement of nanosheet surface energy via emulsion inversion.
• Analysis of surface energy dependence on pH and nanosheet size.

Main Results:

• Surface energy of hydrophilic Ti3C2Tx and graphene oxide decreases with protonation, enhancing emulsion stability.
• Surface energy of pristine graphene and molybdenum disulfide increases with deprotonation under basic conditions.
• Nanosheet size correlates with surface energy, enabling calculation of basal plane and edge energies.

Conclusions:

• The developed method allows for in situ surface energy measurement of 2D materials.
• Understanding surface energy and emulsion inversion is key for designing emulsion-templated structures.
• This work facilitates surface energy studies for a broad range of solution-processable nanomaterials.