| Project/Area Number |
17540380
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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 |
Biophysics/Chemical physics
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| Research Institution | JapanAdvanced Institute of Science and Technology |
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Principal Investigator |
SANO Haruyuki JapanAdvanced Institute of Science and Technology, School of Materials Science, Research Associate, マテリアルサイエンス研究科, 助手 (80250843)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 2006: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2005: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | hydration structure / molecular adsorption / biomaterial / nonlinear optics / sum frequency generation / vibrational spectroscopy |
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| Research Abstract |
In the study of biomaterial surfaces, hydration of a solid surface covered with organic molecules or metal oxide thin film is an important problem. In order to clarify hydration structure at various materials surfaces, optical sum frequency generation (SFG) spectroscopy was used.
1. The effect of polymers weakly adsorbed on a quartz surface on the structure of the interfacial water molecules was investigated. As polymers, PEG, PPG, and two types of tri-block copolymer of Pluronic L64 and 17R-4 were used. SF intensity spectra of OH stretching mode of water molecules at the interface between a quartz substrate and aqueous solutions of the polymers were measured. The total SF intensity of the interfacial water of the L64 aqueous solution was smaller than those of other solutions. This result indicates that the L64 aqueous solution has smaller number of oriented interfacial water molecules. It is suggested that the rapid motion of hydrophilic parts of the adsorbed L64 disturbs the average orientation of the interfacial water molecules. On the other hand, the SF intensity from the interfacial water molecules of aqueous solutions with high ion strength did not depend on the species of the polymers in the solutions. The latter result suggests that the hydration of ions determines the structure of the interfacial water molecules.
2. Hydration structure on a titanium dioxide (TiO_2) surface was observed by SF spectroscopy. It was found that as compared with a glass surface, TiO_2 surface in acidic solution has a large amount of oriented interfacial water molecules.
3. Amino-terminated and fluoroalkyl-terminated glass surfaces were also investigated. It is suggested that hydration structures on these surfaces result from competition of electrostatic interaction, hydrogen bonding, and hydrophobic interaction.
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