Ti₃C₂T MXene Liquid Crystal: Access to Create Background-Free and Easy-Made Alignment Medium

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Lyotropic liquid crystals (LCs) from 2D colloidal dispersions enable ordered materials from nanoscale building blocks.
• MXene LCs, unlike graphene oxide LCs, are underexplored for practical applications.
• Residual dipolar coupling (RDC) measurements require effective alignment media for accurate analysis of organic molecules.

Purpose of the Study:

• To develop a versatile fabrication method for Ti3C2Tx MXene liquid crystals (LCs).
• To evaluate Ti3C2Tx LCs as a background-free alignment medium for RDC measurements.
• To investigate the properties and potential of MXene-based LCs for NMR applications.

Main Methods:

• Fabrication of Ti3C2Tx MXene liquid crystals (LCs) using a simple and versatile method.
• Characterization of LC alignment degree dependence on nanoflake size and concentration.
• Utilizing Ti3C2Tx LCs as an alignment medium for residual dipolar coupling (RDC) measurements of organic molecules.
• Investigating the stability of LC alignment after freeze-drying and re-dispersion.

Main Results:

• Ti3C2Tx LCs exhibit size- and concentration-dependent alignment.
• Nanoflakes (~600 nm) achieved 71 Hz 2H splitting at 50 mg/mL with excellent fluidity.
• Ti3C2Tx LCs provided background-free, narrow-line NMR spectra for accurate RDC extraction.
• LC alignment was maintained after freeze-drying and re-dispersion, simplifying preparation and preservation.

Conclusions:

• Ti3C2Tx MXene LCs are effective, background-free alignment media for RDC measurements.
• The developed MXene LCs offer advantages in spectral quality and ease of use.
• MXene family materials show broad potential for creating diverse alignment media for NMR.