title: Kinetics of aqueous lubrication in the hydrophilic hydrogel Gemini interface.
abstract: The exquisite sliding interfaces in the human body share the common feature of hydrated dilute polymer mesh networks. These networks, especially when they constitute a sliding interface such as the pre-corneal tear film on the ocular interface, are described by the molecular weight of the polymer chains and a characteristic size of a minimum structural unit, the mesh size, ξ. In a Gemini interface where hydrophilic hydrogels are slid against each other, the aqueous lubrication behavior has been shown to be a function of sliding velocity, introducing a sliding timescale competing against the time scales of polymer fluctuation and relaxation at the surface. In this work, we examine two recent studies and postulate that when the Gemini interface slips faster than the single-chain relaxation time, chains must relax, suppressing the amplitude of the polymer chain thermal fluctuations.
authors.affiliation: Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA acd@illinois.edu.
authors.forename: Alison C
authors.initials: AC
authors.lastname: Dunn
authors.affiliation: Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL, USA.
authors.forename: Angela A
authors.initials: AA
authors.lastname: Pitenis
authors.affiliation: Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL, USA.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Urueña
authors.affiliation: Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL, USA.
authors.forename: Kyle D
authors.initials: KD
authors.lastname: Schulze
authors.affiliation: Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL, USA J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA Institute for Cell Engineering and Regenerative Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Angelini
authors.affiliation: Department of Mechanical & Aerospace Engineering, University of Florida, Gainesville, FL, USA Department of Materials Science & Engineering, University of Florida, Gainesville, FL, USA.
authors.forename: W Gregory
authors.initials: WG
authors.lastname: Sawyer
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000869:Anterior Eye Segment / Q000502:physiology; D005143:Eyelids / Q000502:physiology; D017276:Friction; D006801:Humans; D020100:Hydrogels / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D054327:Lubricants / Q000737:chemistry*; D008153:Lubrication; D008954:Models, Biological; D013666:Tears / Q000502:physiology; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D020100:Hydrogels; D054327:Lubricants; D000099166:Polyacrylamides; C052970:poly-N-isopropylacrylamide
keywords: Hydrogel; friction; mesh size; polyacrylamide; tribology of materials