Spreading Behavior of Lubricant Films

The self-healing/spreading capability of perfluoropolyether (PFPE) film is critical to handle recurring contacts as well to the long-term reliability of drives. Here the spontaneous spreading of lubricant nanofilms on carbon overcoats via optical surface analyzer (OSA) and molecular dynamics (MD) simulations to demonstrate molecular conformation as well as diffusion characteristics was investigated. Fractionated PFPE Z and Zdol films with various thicknesses were partially dip-coated on commercial Seagate disks. The spreading profiles were then measured using OSA by tracing the same cross section, perpendicular to the sharp boundary between lubricated and bare disk surfaces. The spreading profiles of PFPE and Zdol monolayers with different molecular weight (MW) and initial thickness were plotted.