title: Stick-slip control in nanoscale boundary lubrication by surface wettability.
abstract: We study the effect of atomic-scale surface-lubricant interactions on nanoscale boundary-lubricated friction by considering two example surfaces-hydrophilic mica and hydrophobic graphene-confining thin layers of water in molecular dynamics simulations. We observe stick-slip dynamics for thin water films confined by mica sheets, involving periodic breaking-reforming transitions of atomic-scale capillary water bridges formed around the potassium ions of mica. However, only smooth sliding without stick-slip events is observed for water confined by graphene, as well as for thicker water layers confined by mica. Thus, our results illustrate how atomic-scale details affect the wettability of the confining surfaces and consequently control the presence or absence of stick-slip dynamics in nanoscale friction.
authors: Department of Applied Physics, COMP Centre of Excellence, Aalto University, P.O. Box 11100, 00076 Aalto, Espoo, Finland.|Supercomputing Center of CAS, Computer Network Information Center, Chinese Academy of Sciences, Beijing 100190, China.
authors: Wei
authors: W
authors: Chen
authors: Department of Applied Physics, COMP Centre of Excellence, Aalto University, P.O. Box 11100, 00076 Aalto, Espoo, Finland.
authors: Adam S
authors: AS
authors: Foster
authors: Department of Applied Physics, COMP Centre of Excellence, Aalto University, P.O. Box 11100, 00076 Aalto, Espoo, Finland.
authors: Mikko J
authors: MJ
authors: Alava
authors: Department of Applied Physics, COMP Centre of Excellence, Aalto University, P.O. Box 11100, 00076 Aalto, Espoo, Finland.
authors: Lasse
authors: L
authors: Laurson
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D017276:Friction; D006108:Graphite / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D054327:Lubricants / Q000737:chemistry*; D008153:Lubrication; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D036103:Nanotechnology / Q000379:methods*; D013499:Surface Properties; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D000538:Aluminum Silicates; D054327:Lubricants; D014867:Water; D006108:Graphite; C011934:mica