The Static and Dynamic Responses of Binary Mixture Perfluoropolyether Lubricant Films- Molecular Structural Effects

• Published in: IEEE transactions on magnetics 2009-10, Vol.45 (10), p.3644-3647
• Main Authors: Pil Seung Chung, Hakhee Park, Jhon, M.S.
• Format: Article
• Language: English
• Subjects: Bead-spring model; binary mixtures; Chemical engineering; Computer simulation; Cross-disciplinary physics: materials science; rheology; Data engineering; Data storage systems; diffusion coefficient; Disk drives; Dynamics; Exact sciences and technology; Extraterrestrial phenomena; head-disk interface; Knowledge engineering; Lubricants; Lubricants & lubrication; Magnetism; Maintenance; Materials science; Materials science and technology; Mathematical models; molecular dynamics; Molecular structure; Nanocomposites; Nanomaterials; Nanostructure; Other topics in materials science; perfluoropolyethers; Physics; Polymers
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2009.2022841

Static and dynamic properties of single-component perfluoropolyether (PFPE) lubricants have been studied for optimal lubricant selection by examining the molecular conformations that influence the thickness and the mobility for the self-healing capability in lubricant nanofilms. In this paper, we examine the physiochemical properties of the mixture of these two PFPEs using molecular dynamics (MD) simulations to find an optimal blend ratio to meet the stringent requirements for disk lubricants of ultra-low head media spacing (HMS). A coarse-grained, bead-spring model was used to model the polymer nanoblends using functional and nonfunctional PFPEs. We examined the static and dynamic responses of binary PFPE films as a function of the molecular structures including end-group functionality. The effect of the functional end-group on the static structures was examined by simulating the parallel and perpendicular components of the radius of gyration. The dynamic responses of various PFPE nanoblends were also simulated by explicitly calculating the self-diffusion coefficient of a tagged molecule. Polydispersity effect on nanoblends was also examined.