MOLECULAR-DYNAMICS SIMULATION OF THE APPROACH AND WITHDRAWAL OF A MODEL CRYSTALLINE METAL TO A SILICA GLASS-SURFACE

Room temperature interfacial atomistic behavior between a model Lennard-Jones Pt (111) crystalline surface and a silica glass surface was investigated using classical molecular dynamics simulations. The approach and pulloff of the crystalline surface to two silica glass surfaces was simulated. During approach, both simulated interfaces evolved from a state of tensile to compressive stress parallel to the direction of approach. Compression of both glass surfaces occurred with accompanying structural shifts that created coordination defects and small rings with strained siloxane bonds in the glasses. Upon pulloff, the system stress again went through a tensile region and, for both interfaces, the maximum tensile stress on pulloff exceeded that of the approach. In both glass surfaces, the relaxation accompanying pulloff of the crystal did not result in complete removal of the defects created during the cycle. The results have important implications with respect to the reactivity of glass surfaces during and after compressive contact with a crystalline phase. © 1994 American Institute of Physics.