Triboelectron emission from metal surfaces in sliding contact with polytetrafluoroethylene: Relevance to work function and surface potential

The mechanism of the triboelectron emission (TriboEE) occurring in sliding contact between metals and polytetrafluoroethylene (PTFE) has been investigated. The mapping of the TriboEE intensity for 16 kinds of metals onto the periodic table revealed that the order of the TriboEE intensity between two adjoining metals in the same period was well correlated with that of the work function and photoelectric threshold of metal samples and with that of the surface potential of metal samples and mated PTFE riders after the TriboEE measurement. The relationship of TriboEE intensity to the electronegativity, the ionization energy, and the electron affinity of the elements and the electrical conductivity of metals was also examined.