Direct mechanochemical cleavage of functional groups from graphene

Area of Science:

• Materials Science
• Surface Chemistry
• Nanotechnology

Background:

• Mechanical stress can initiate and influence chemical reactions, a phenomenon known as mechanochemistry.
• Understanding the relationship between applied force and bond scission is challenging due to the complex nature of mechanical inputs.

Purpose of the Study:

• To develop and demonstrate a novel atomic force microscope (AFM) technique for real-time measurement of mechanically induced bond scission.
• To quantitatively investigate the dynamics of stress-driven reactions at the atomic scale.

Main Methods:

• Utilized a specialized atomic force microscope (AFM) setup to apply and measure mechanical forces at the atomic level.
• Monitored bond scission events in real-time on graphene substrates with different chemical functional groups.

Main Results:

• The study successfully measured the real-time dynamics of mechanically induced bond scission on graphene.
• Reaction rates were found to be dependent on the specific bond being broken (e.g., oxygen, fluorine, hydrogen) and the AFM tip material.
• Demonstrated that oxygen cleaves from graphene more readily than fluorine, and fluorine more readily than hydrogen.

Conclusions:

• The developed AFM technique provides unprecedented sensitivity to atomic-scale mechanochemical interactions.
• This method offers a powerful new tool for studying the mechanochemistry of various material and chemical combinations.
• The findings highlight the importance of force directionality and material properties in stress-driven chemical reactions.