| Project/Area Number |
09640711
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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 |
分離・精製・検出法
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
SHIMAZU Katsuaki Hokkaido Univ., Grad. School of Environmental Earth science, Assoc. Prof., 大学院・地球環境科学研究科, 助教授 (30109417)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Self-assembly / Surface Mass Titration / Quartz Crystal Microbalance / Surface pKa / Reductive Desorption / Interfaclal Solvation / 酸解離定数 / 表面質量適定法 / セルフアセンブリ単分子層 / 電位効果 / メルカプトアルキルカルボン酸 / ポリビニルピリジン |
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| Research Abstract |
The evaluation of surface acid/base properties of self-assembled thiol monolayers (SAMs) on gold has been conducted using the surface mass titration method we have developed in this project. The surface mass titratioh, in which the mass change of the electrode surface due to ion association is measured during the titration of SAMs using a quartz crystal microbalance, has the capability of evaluating both the surface pKa and acid density of SAMs simultaneously. We have examined effects of chain length, electrolyte solutions and surface acid density in single component and mixed SAMs on the surface pKa of COOH- and NH2-terminated SAMs. It is demonstrated by these results that the surface pKa is dependent on the structure of SAM or how acid/base centers are distributed. The main origin of this dependence is concluded to be the lateral repulsive interaction between the surface charged species formed by acid/base equilibrium. We also found that the surface pKa is controllable by the electrode potentials: the pKa shifted to negative direction when negative potentials were applied. The ion association between terminal COOH and cation in solution was examined in detail in order to clarify the origin of mass change during the titration. Based on mass measurements of desorbed COOH-terminated thiol, we conclude that the solvated cation is associated with the terminal carboxylate of SAM. The solvation number is also determined for LiィイD1+ィエD1, KィイD1+ィエD1 and CsィイD1+ィエD1.
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