title: Self-accumulation of aromatics at the oil-water interface through weak hydrogen bonding.
abstract: It is well-known that the amphiphilic solutes are surface-active and can accumulate at the oil-water interface. Here, we have investigated the water and a light-oil model interface by using molecular dynamic simulations. It was found that aromatics concentrated in the interfacial region, whereas the other hydrocarbons were uniformly distributed throughout the oil phase. Similar to previous studies, such concentrations were not observed at pure aromatics-water interfaces. We show that the self-accumulation of aromatics at the oil-water interface is driven by differences in the interfacial tension, which is lower for aromatics-water than between the others. The weak hydrogen bonding between the aromatic rings and the water protons provides the mechanism for lowering the interfacial tension.
authors.affiliation: Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kunieda
authors.forename: Kennichi
authors.initials: K
authors.lastname: Nakaoka
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Liang
authors.forename: Caetano R
authors.initials: CR
authors.lastname: Miranda
authors.forename: Akira
authors.initials: A
authors.lastname: Ueda
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okabe
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Matsuoka