The lubricant. perfluoropolyethers (PFPEs). has been modeled and analyzed using molecular dynamics simulations based on a coarse-grained bead-spring model. An ultrathin lubricant film with a thickness of 1-2 nm is coated on a disk to lubricate the head disk interface (HDI) of hard disk drives (HDDs). https://thegreensjunglebeautyshops.shop/product-category/brow-pencil/