ELECTRICAL PHENOMENA ACCOMPANYING THE FORMATION OF NEW SURFACES, AND THEIR ROLE IN ADHESION AND COHESION

Upon tearing off polymer films from metals and glasses phenomena are o bserved which testify to the apparition of high differences of potenti als between the interfaces formed. In particular, if the film is strip ped under vacuum, electron emission is observed with electron velociti es of the order of kilovolts. These phenomena are due to division upon stripping of the double electric layer, formed upon close contact bet ween the polymer and the substrate, and to retardation of its discharg e. The same retardation of the discharge of the double layer may expla in quantitatively both the high value of the work spent on tearing off the film, the dependence of the latter on the speed of stripping and on the pressure of surrounding gas. Similar phenomena were found to ta ke place during the destruction of many crystalline (but not amorphous ) solids and are explained by the formation and division of an alterna ting-sign double layer of mosaic structure.