Effects of Intercalation on ML-Ti₃C₂T MXene Properties and Friction Performance

Area of Science:

• Materials Science
• Tribology
• Nanotechnology

Background:

• Intercalation in two-dimensional (2D) materials alters physical, chemical, and electronic properties, enabling tailored material characteristics for diverse applications.
• The friction performance of 2D materials like MoS2 and graphite is strongly dependent on interlayer spacing (d-spacing), with increased d-spacing typically reducing friction.
• While controlling Ti3C2Tx MXene interlayer spacing is established for energy storage, its application in lubrication remains unexplored.

Purpose of the Study:

• To demonstrate the control of interlayer spacing in multilayer (ML) Ti3C2Tx MXene via chemical intercalation.
• To investigate the effects of controlled interlayer spacing on the electrical conductivity and friction performance of ML-Ti3C2Tx MXene.
• To explore the potential of MXene materials for lubrication applications by tuning their tribological properties.

Main Methods:

• Chemical intercalation was employed to modify the interlayer spacing of multilayer Ti3C2Tx MXene.
• Vacuum filtration was used to prepare ML-Ti3C2Tx MXene films.
• Electrical conductivity and friction performance (coefficient of friction) were measured to evaluate the effects of intercalation.

Main Results:

• A notable decrease in electrical conductivity was observed in intercalated ML-Ti3C2Tx MXene films, attributed to increased internal resistance from expanded interlayer gaps.
• A significant reduction in the coefficient of friction was achieved for ML-Ti3C2Tx MXene with increased d-spacing.
• The reduced friction is attributed to weakened van der Waals forces between intercalated layers, facilitating easier sliding within the expanded interlayer gaps.

Conclusions:

• Chemical intercalation effectively controls the interlayer spacing of ML-Ti3C2Tx MXene, influencing its electrical and tribological properties.
• Expanded interlayer spacing in ML-Ti3C2Tx MXene leads to decreased electrical conductivity but significantly enhanced lubrication performance.
• This study highlights the tunability of MXene properties through interlayer spacing, presenting potential for applications requiring specific electrical and friction characteristics.