(552i) A Nanometer-Thick Ionic Liquid As Media Lubricant in Hard Disk Drives

Media lubricants are essential to the reliability and function of hard disk drives (HDDs). In addition to a low coefficient of friction (CoF), a good media lubricant should have surface-bonding capabilities with low surface tension for self-healing properties, high thermal stability for heat-assisted magnetic recording (HAMR), and a low monolayer thickness to minimize head media spacing (HMS). Traditionally, the state-of-the-art lubricants have been functionalized perfluoropolyethers (PFPEs). However, the bulky molecular size of these polymer-based lubricants is a limiting factor in the reduction of the HMS. Ionic liquids (ILs) are a promising replacement due to their high thermal stability and relatively small size. Previously, our research has shown that commercial ILs struggle to match the bonded thickness, low surface tension, and low CoF that the PFPEs have achieved. Here we demonstrate the successful development of a novel functionalized ionic liquid with highly fluorinated alkyl segments. In addition to the benefits of commercial ILs, our lubricant displays a comparable CoF to the PFPE Ztetraol, but has a lower surface tension and maintains a stable bonded thickness. These results demonstrate that the novel IL has strong potential to be the next-generation lubricant for HDDs.