title: Unifying interfacial self-assembly and surface freezing.
abstract: X-ray investigations reveal that the monolayers formed at the bulk alkanol-sapphire interface are densely packed with the surface-normal molecules hydrogen bound to the sapphire. About 30-35 °C above the bulk, these monolayers both melt reversibly and partially desorb. This system exhibits balanced intermolecular and molecule-substrate interactions which are intermediate between self-assembled and surface-frozen monolayers, each dominated by one interaction. The phase behavior is rationalized within a thermodynamic model comprising interfacial interactions, elasticity, and entropic effects. Separating the substrate from the melt leaves the monolayer structurally intact.
authors.affiliation: Condensed Matter Physics & Materials Sciences Department, Brookhaven National Laboratory, Upton, New York 11973, USA. ocko@bnl.gov
authors.forename: B M
authors.initials: BM
authors.lastname: Ocko
authors.forename: H
authors.initials: H
authors.lastname: Hlaing
authors.forename: P N
authors.initials: PN
authors.lastname: Jepsen
authors.forename: S
authors.initials: S
authors.lastname: Kewalramani
authors.forename: A
authors.initials: A
authors.lastname: Tkachenko
authors.forename: D
authors.initials: D
authors.lastname: Pontoni
authors.forename: H
authors.initials: H
authors.lastname: Reichert
authors.forename: M
authors.initials: M
authors.lastname: Deutsch
mesh_terms: D000438:Alcohols / Q000737:chemistry*; D000537:Aluminum Oxide / Q000737:chemistry*; D005615:Freezing; D013499:Surface Properties; D013696:Temperature
chemical_list: D000438:Alcohols; D000537:Aluminum Oxide