title: Formation of n-alkane layers at the vapor/water interface.
abstract: We present a study on the initial wetting behaviors of two low molecular weight alkanes, heptane and octane, at the vapor/water interface using both neutron and X-ray reflectometry. Combined X-ray and neutron reflectivity studies data showed that a uniform film, which has never been reported, was formed continuously at 25 degrees C. As the adsorptive deposition continued, each adsorbed film was saturated at a specific equilibrium thickness: 48 and 36 A for deuterated heptane and octane, respectively, and 21 A for hydrogenated octane. The thickness of the adsorbed layer measured by neutron reflectivity is in agreement with that measured using X-ray reflectivity. Our observations of continuous and saturated adsorption behaviors are analyzed qualitatively using a kinetic adsorption model.
authors.affiliation: Department of Chemistry and Program of Integrated Biotechnology, Sogang University, Shinsoo, Mapogu, Seoul, Korea.
authors.forename: Oh-Sun
authors.initials: OS
authors.lastname: Kwon
authors.forename: Huaiyu
authors.initials: H
authors.lastname: Jing
authors.forename: Kwanwoo
authors.initials: K
authors.lastname: Shin
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Wang
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Satija
mesh_terms: D000042:Absorption; D000473:Alkanes / Q000737:chemistry*; D005740:Gases; D006536:Heptanes / Q000737:chemistry; D006865:Hydrogenation; D008970:Molecular Weight; D009502:Neutrons; D009795:Octanes / Q000737:chemistry; D012542:Scattering, Radiation; D013499:Surface Properties; D013696:Temperature; D014835:Volatilization; D014867:Water / Q000737:chemistry*
chemical_list: D000473:Alkanes; D005740:Gases; D006536:Heptanes; D009795:Octanes; D014867:Water; C026728:octane