| Project/Area Number |
05640643
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
機能・物性・材料
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| Research Institution | Hokkaido University |
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Principal Investigator |
SAKURAI Masao Hokkaido Univ., Fac.of Sci., Assistant, 理学部, 助手 (70002251)
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| Co-Investigator(Kenkyū-buntansha) |
NITTA Katsutosi Hokkaido Univ., Fac.of Sci., Professor, 理学部, 教授 (80001858)
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| Project Period (FY) |
1993 – 1994
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| Project Status |
Completed (Fiscal Year 1994)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1994: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1993: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Super Cooling / Anti-freeze Glycoprotein / Aqueous Solutions / Volumetric Behavior / Partial Molar Quantity / Hydrophobic Hydration / Block Copolymer / Conformational Transition / 疎水-親水性高分子 |
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| Research Abstract |
The volumetric behavior of various low-molecular and high-molecular weight substances in aqueous solutions were studied in order to obtain information on solute-water interactions at low temperatures.Knowlegde of the hydrophilic and hydrophobic interactions would be of interest in problems relating to anti-freeze mechanism by glycoproteins.Freezing point depressions by some soluble polymers were measured and compared with the anti-freeze glycoproteins.
1.The densities and sound velocities of aqueous alcohola, alkyl acetates, and amino acid derivatives were measured.On the basis of the temperature dependences of the partial molar volumes and adiabatic compressions, we discussed the hydrophilic and hydophobic hydrations.No characteristic volumetric behavior was found in solutions of a series of hydrophobic alkyl acetates.We concluded that some anomalous behavior observed for alcohols or amines at low temperatures may be attributed to hydrophilic interactions rather than hydrophobic interactions.
2.The viscosities, densities and sound velocities were measured for block copolymer of poly (ethylene oxide) and poly (propylene oxide) at various temperatures.The conformational transition was observed at about 30ﾟC.This transition may result from the intramolecular hydrophobic interactions between poly (propylene oxide) chains.At low temperatures, the polymer segments hydrate strongly and therefore, the chain expands very well.The partial specific volume or compression also varies steeply at this transition temperature.
3.Freezing point depressions were measured for the aqueous solutions of some synthetic polymers.We found much larger depressions than that expected from colligative properties.However, the mechanism of extra depressions by simple polymers may differ from anti-freeze glycoproteins.Since little reliable data are available for soluble polymers, it is inevitable to investigate more systematically concerning the freezing behavior of simple polymer solutions.
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