Bipolar Tribocharging Signal During Friction Force Fluctuations at Metal–Insulator Interfaces†
Work at the Argonne National Laboratory and use of the Center for Nanoscale Materials was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences (DE-AC02-06CH11357). We also thank Dr. Osman Levent Eryilmaz for assistance with photography.
Abstract
Reibungskraftfluktuationen und Triboelektrifizierung an Metall-Isolator-Grenzflächen sind bei Schleifkontakten stark korreliert. Neue Ergebnisse lassen vermuten, dass diese Phänomene einen gemeinsamen Ursprung haben, der mit den starken elektrostatischen Wechselwirkungen an der Grenzfläche zusammenhängt.
Abstract
Friction and triboelectrification of materials show a strong correlation during sliding contacts. Friction force fluctuations are always accompanied by two tribocharging events at metal–insulator [e.g., polytetrafluoroethylene (PTFE)] interfaces: injection of charged species from the metal into PTFE followed by the flow of charges from PTFE to the metal surface. Adhesion maps that were obtained by atomic force microscopy (AFM) show that the region of contact increases the pull-off force from 10 to 150 nN, reflecting on a resilient electrostatic adhesion between PTFE and the metallic surface. The reported results suggest that friction and triboelectrification have a common origin that must be associated with the occurrence of strong electrostatic interactions at the interface.





