Film Conformation and Dynamic Properties of Atomistically Architectured Perfluoropolyethers on the Carbon Overcoated Surfaces

To improve chemical and thermal stability under harsh conditions, conventional linear perfluoropolyether (PFPE) lubricants with chain-like structures need to be molecularly modified. We investigated the molecular conformations and dynamic properties of star-like PFPEs (i.e., TA-30 and QA-40) chosen as a candidate lubricant material for the heat-assisted magnetic recording system and compared those results to the other molecularly architectured PFPEs (i.e., Zdol, Ztetraol, and ZTMD) via multiscale modeling methodology. Due to the improved adhesion of the extra arms to the surface, star-like PFPEs exhibit excellent thermal stability, while additional functional groups cause agglomeration by drastically decreasing mobility on the carbon overcoat. The effect of PFPE molecular structures on the static and dynamic responses examined here could provide the molecular design criteria for the advanced head-disk interface design.