Direct mechanochemical cleavage of functional groups from graphene.
Mechanical stress can drive chemical reactions and is unique in that the reaction product can depend on both the magnitude and the direction of the applied force. Indeed, this directionality can drive chemical reactions impossible through conventional means. However, unlike heat- or pressure-driven reactions, mechanical stress is rarely applied isometrically, obscuring how mechanical inputs relate to the force applied to the bond. Here we report an atomic force microscope technique that can measure mechanically induced bond scission on graphene in real time with sensitivity to atomic-scale interactions. Quantitative measurements of the stress-driven reaction dynamics show that the reaction rate depends both on the bond being broken and on the tip material. Oxygen cleaves from graphene more readily than fluorine, which in turn cleaves more readily than hydrogen. The technique may be extended to study the mechanochemistry of any arbitrary combination of tip material, chemical group and substrate.
Mechanical Engineering Department, Texas A&M University, 3123 TAMU, College Station, Texas 77843, USA.
Jonathan R
JR
Felts
National Research Council, US Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, District Of Columbia 20375, USA.
Andrew J
AJ
Oyer
Plasma Physics Division, US Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, District Of Columbia 20375, USA.
Sandra C
SC
Hernández
National Research Council, US Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, District Of Columbia 20375, USA.
Keith E
KE
Whitener
Electronics Science and Technology Division, US Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, District Of Columbia 20375, USA.
Jeremy T
JT
Robinson
Plasma Physics Division, US Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, District Of Columbia 20375, USA.
Scott G
SG
Walton
Chemistry Division, US Naval Research Laboratory, Washington, District Of Columbia 20375, USA.
Paul E
PE
Sheehan