Effect of surface hydroxylation on ultra-precision machining of quartz glass

[Display omitted] •H atoms dissociating from H2O present a weakening effect on SiO bonds.•Dehydrogenation and dehydroxylation are key to form SiOSi bonds.•Dehydroxylation contribute to remove materials of quartz glass in CMP process.•Surface modification of quartz glass can improve its machinability. Chemical mechanical polishing is a main technology to flatten the surface of quartz glass. However, the role of water in polishing slurry and the removal mechanism in the CMP process of quartz glass are still unclear. The simulation based on ReaxFF-MD method was utilized to explore the microphenomenon and the removal mechanism in the CMP process of quartz glass. The simulation results indicated that the H atoms dissociating from H2O in polishing slurry present a weakening effect on SiO bonds in quartz glass. Besides, the hydroxylation process when the pristine surface of quartz glass reacts with OH groups dissociating from H2O was elucidated explicitly in this simulation. To verify the correctness of this ReaxFF-MD simulation, a set of experiments including nanoindentation and nanoindentation were implemented on quartz glass modified in solutions with different concentrations of aqueous H2O2 and KOH. According to the results of experiments, surface modification of quartz glass contributes to the removal of surface materials and processability of quartz glass modified by 5% aqueous H2O2 is the best. This work combining simulations and experiments contribute to understand the chemical behavior of nanoparticles at the atomic scale and provide an effective method to choose the CMP slurry.