title: Humidity effects on anisotropic nanofriction behaviors of aligned carbon nanotube carpets.
abstract: We evaluated the interfacial properties of vertically and transversely aligned multiwalled carbon nanotubes (CNTs) carpets using atomic force microscopy (AFM) under ambient (26%-52% relative humidity (RH)), mild (10% RH), and dry conditions (<3.3% RH). The frictional forces on a transversely aligned CNT (TAMWCNT) surface are lower than those on a vertically aligned CNT (VAMWCNT) surface, and they decrease as the relative humidity decreases for both TAMWCNT and VAMWCNT surfaces. Similar trends are found for adhesion forces on both surfaces. Contact mechanics theories are applied and compared in an attempt to better understand these results. The tribological behavior of CNT carpets unveiled in this paper is expected to inspire tunable friction surface engineering strategies.
authors.affiliation: Department of Mechanical Engineering and Materials Science, Rice University , Houston, Texas 77005, United States.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Lu
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.forename: L
authors.initials: L
authors.lastname: Ci
authors.forename: P M
authors.initials: PM
authors.lastname: Ajayan
authors.forename: J
authors.initials: J
authors.lastname: Lou
mesh_terms: D016880:Anisotropy; D017276:Friction; D006813:Humidity; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D013499:Surface Properties
chemical_list: D037742:Nanotubes, Carbon