Structure of CAS glass surfaces and electrostatic contact charging behavior: A joint simulation and experimental investigation
Gabriel Agnello, Liaoyuan Wang, Nicholas J. Smith, Robert G. Manley, Alastair N. Cormack
Abstract
Abstract Surface structures of CAS models with various Al 2 O 3 /CaO ratios, (80:10:10), (70:15:15), (60:20:20), and (50:25:25), have been simulated using classical MD methods. Atomistic surface structures, CN and Q n distributions, radial distribution functions, z‐axis concentration profiles, and ring‐size distributions were employed to study the surface structures. While bridging oxygen (BO) and triclustered oxygen (TBO) surface concentrations closely mimic those observed in the bulk structures, nonbridging oxygen (NBO) concentration exhibits a nonlinear trend with composition. Surface analysis has also showed that both 3‐ and 5‐coordinated Al (Al C3 and Al C5 ) exist in the near‐surface region, with concentrations that differ from the respective bulk structures. There are enhancements in the concentrations of small (2‐ and 3‐membered) rings that are closely related with the spatial proximity of TBO to Al C5 . These complexes, and their variations with glass composition, appear to be closely correlated with experimental electrostatic contact charging data.