Molecular level structure analysis of Gibbs film stabilized by interaction between mesoscopic domains
| Project/Area Number |
16550017
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | KYUSHU UNIVERCITY |
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Principal Investigator |
TAKIUE Takanori Kyushu University, Science, Chemistry, Associate Professor, 大学院理学研究院, 助教授 (40271100)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Keywords | Gibbs film / mesoscopic domains / X-ray reflectivity / oil / water interface / multilayer formation / ギブス膜 / 界面不均一構造 / 界面構造化学 / ギブズ膜 / ω位双極子 |
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| Research Abstract |
Recent development of spectroscopic technique enables us to analyze the structure of interfacial films at gas/liquid interfaces from molecular level. However, the structure analysis of interfacial films at liquid/liquid interfaces has not been well organized yet, although it gives fundamental information about the structure and property of molecular organized systems such as microemulsion, vesicles, biomembranes, and so on. This study aim at elucidating the relationship between function and structure in biological system on the basis of structure analysis of Gibbs films at liquid/liquid interfaces.
During the research for three years, the Gibbs films of fluorocarbon (FC) and hydrocarbon (HC) alcohols at the hexane/water interface was examined by interfacial tension and synchrotron X-ray reflectivity measurements. The noticeable results obtained are as follows.
1. Interfacial tension study
The interfacial tensions of the hexane solution of solutes against water were measured as a function
… More
of temperature, pressure, and concentration. The experimental data was analyzed in terms of rigorous thermodynamics of interfaces to obtain interfacial density, entropy and volume of adsorption, phase diagram of adsorption, and excess thermodynamic quantities of adsorption.
(1) The adsorbed FC alcohol films exhibit phase transition between gaseous (or expanded) and condensed states.
(2) FC alcohols mix with HC alcohol in the expanded film, while are immiscible in the condensed film because of very weak mutual interaction between FC and HC chains.
(3) FC alcohols become to be miscible with cationic surfactant with HC chain (DTAB) due to strong attractive interaction of hydroxyl group with cationic head group.
(4) In the mixed system of FC alcohol-DTAB, Gibbs film form multilayer spontaneously.
2. X-ray reflectivity study
In order to determine the structure of Gibbs films found in the interfacial tension study, the X-ray reflectivity measurements were performed at BL-X19C in NSLS of Brookhaven National Laboratory (USA) as a function of temperature at fixed concentration. The results obtained were ;
(1) FC and HC alcohols are closely packed in the condensed film like two-dimensional solid state.
(2) The Gibbs films are inhomogeneous by coexisting condensed phase domains with very low density gaseous film near phase transition temperature.
(3) The total reflectivity in the condensed film is lower for FC alcohol-DTAB system is lower than for the condensed films of single FC alcohol systems. This suggests the mixing of FC alcohol and DTAB in the condensed state.
(4) The oscillation of reflectivity curve supports the multilayer formation in the FC alcohol-DTAB system. Less
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Report
(4 results)
Research Products
(15 results)
