Adhesion, friction and tribochemical reactions at the diamond–silica interface

Diamond-based coatings are employed in several technological applications, for their outstanding mechanical properties, biocompatibility, and chemical stability. Of significant relevance is the interface with silicon oxide, where phenomena of adhesion, friction, wear can affect drastically performance coating. Here we monitor such real-time by performing massive ab initio molecular dynamics simulations tribological conditions. We take into account many relevant factors that play a role, i.e. diamond surface orientation reconstruction, silanol density, as well as, type concentration passivating species. The large systems size long time, put our work at frontier what be currently done fully dynamics. results point to full hydrogenation an effective way reduce both friction all surfaces, while graphitization competitive only on (111) surface. Overall expect observations will useful improve applications silica-diamond plays key role. Moreover, demonstrate realistic accurate silico experiments feasible nowadays exploiting HPC resources optimized software, paving more general understanding relationship between chemistry nanoscale-tribology.