THE CONTACT ELECTRIFICATION OF POLYMERS AND THE DEPTH OF CHARGE PENETRATION

Measurements of contact electrification have been made on polymer film s charged by repeated contacts to mercury. In these studies the satura tion surface potential of monodisperse polystyrene has been measured a s a function of film thickness, and we show that charges appear to be trapped within about 30 nm of the surface. In a related series of expe riments, using an electron beam to inject into the free surface of pol ystyrene films, we find that the electron range is several mu m. A rea son for this large difference in charge penetration distance is presen ted.