3
|
Kunieda M, Nakaoka K, Liang Y, Miranda CR, Ueda A, Takahashi S, Okabe H, Matsuoka T. Self-Accumulation of Aromatics at the Oil−Water Interface through Weak Hydrogen Bonding. J Am Chem Soc 2010; 132:18281-6. [DOI: 10.1021/ja107519d] [Citation(s) in RCA: 134] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Makoto Kunieda
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Kennichi Nakaoka
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Yunfeng Liang
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Caetano R. Miranda
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Akira Ueda
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Satoru Takahashi
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Hiroshi Okabe
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| | - Toshifumi Matsuoka
- Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan, Universidade Federal do ABC, Rua Santa Adélia, 166 Bangu 09210-170, Santo André, SP Brazil, and Japan Oil, Gas and Metals National Corporation, Chiba 261-0025, Japan
| |
Collapse
|
8
|
Day JPR, Bain CD. Ellipsometric study of depletion at oil-water interfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 76:041601. [PMID: 17994998 DOI: 10.1103/physreve.76.041601] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Indexed: 05/25/2023]
Abstract
Ellipsometry is exquisitely sensitive to density variations across a fluid-fluid interface. The coefficient of ellipticity at the interface between water and a series of nonpolar and polar oils is the opposite sign to that predicted for an interface roughened by thermal capillary waves. For pure hydrocarbons, the coefficient of ellipticity is correlated with the refractive index of the oil, but is largely independent of the molecular architecture of the oil phase, ruling out molecular alignment at the interface as the major cause of the deviation from the capillary-wave model. The introduction of a "drying" layer between the oil and water can explain the experimental data. The thickness of the drying layer, modeled as a slab with a relative permittivity of unity, was only 0.3-0.4 A, which is close to that expected simply from the hard sphere repulsion of a hydrocarbon surface. For polar oils, the coefficient of ellipticity decreases as the interfacial tension decreases, consistent with the reduction in thickness of the hard-sphere exclusion region on account of the formation of hydrogen bonds to water.
Collapse
Affiliation(s)
- James P R Day
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | | |
Collapse
|
10
|
Allesch M, Schwegler E, Galli G. Structure of Hydrophobic Hydration of Benzene and Hexafluorobenzene from First Principles. J Phys Chem B 2007; 111:1081-9. [PMID: 17266261 DOI: 10.1021/jp065429c] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We report on the aqueous hydration of benzene and hexafluorobenzene, as obtained by carrying out extensive (>100 ps) first principles molecular dynamics simulations. Our results show that benzene and hexafluorobenzene do not behave as ordinary hydrophobic solutes, but rather present two distinct regions, one equatorial and the other axial, that exhibit different solvation properties. While in both cases the equatorial regions behave as typical hydrophobic solutes, the solvation properties of the axial regions depend strongly on the nature of the pi-water interaction. In particular, pi-hydrogen and pi-lone pair interactions are found to dominate in benzene and hexafluorobenzene, respectively, which leads to substantially different orientations of water near the two solutes. We present atomic and electronic structure results (in terms of Maximally Localized Wannier Functions) providing a microscopic description of benzene- and hexafluorobenzene-water interfaces, as well as a comparative study of the two solutes. Our results point at the importance of an accurate description of interfacial water to characterize hydration properties of apolar molecules, as these are strongly influenced by subtle charge rearrangements and dipole moment redistributions in interfacial regions.
Collapse
Affiliation(s)
- Markus Allesch
- Department of Theoretical and Computational Physics, Graz University of Technology, Graz, Austria
| | | | | |
Collapse
|