An interdisciplinary team of engineers from the University of Pennsylvania has made a discovery regarding the surface properties of graphene, the Nobel-prize winning material that consists of an atomically thin sheet of carbon atoms.
On the macroscale, adding fluorine atoms to carbon-based materials makes for water-repellant, non-stick surfaces, such as Teflon. However, on the nanoscale, adding fluorine to graphene had been reported to vastly increase the friction experienced when sliding against the material.
Through a combination of physical experiments and atomistic simulations, the Penn team has discovered the mechanism behind this surprising finding, which could help researchers better design and control the surface properties of new materials.
The research was led by postdoctoral researcher Qunyang Li, graduate student Xin-Zhou Liu and Robert Carpick, professor and chair of the Department of Mechanical Engineering and Applied Mechanics in Penn’s School of Engineering and Applied Science. They collaborated with Vivek Shenoy, a professor in the Department of Materials Science and Engineering. The Penn contingent also...more