1999 Fiscal Year Final Research Report Summary
NANOSCALE CONTROL OF MOLECULAR DISPERSION-PHASE SEPARATION FOR TWO-DIMENSIONAL AGGREGATING SYSTEM
| Project/Area Number |
09450039
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied physics, general
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| Research Institution | SAGA UNIVERSITY |
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Principal Investigator |
OISHI Yushi SAGA UNIVERSITY, DEPARTMENT OF APPLIED CHEMISTRY, ASSOCIATE PROFESSOR, 理工学部, 助教授 (70194074)
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| Project Period (FY) |
1997 – 1999
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| Keywords | MONOLAYER / BINARY SYSTEM / PHASE SEPARATION / COHESIVE ENERGY / MISCIBILITY GAP / SPINODAL DECOMPOSITION / II-A ISOTHERM / SCANNING PROBE MICROSCOPY |
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| Research Abstract |
Surface morphology of Langmuir mixed monolayer was investigated on the basis of a π-A isotherm measurement and a scanning probe microscopic observation. The molecular aggregating behavior of mixed monolayer markedly depended on difference in alkyl chain length, that is, cohesive energy between hydrophobic portions of fatty acids. The mixed monolayers for the cases of 4, 6 and 8 methylene units differences corresponding to 28, 42 and 56 kJ/mol for cohesive energy were in a molecular mixing state, phase separation in a miscibility gap and segregation in an immiscibility system, respectively. In particularly, the phase separated morphology was a co-continuous state, indicating the phase separation due to the spinodal decomposition. Moreover, the molecular aggregating state of the mixed monolayer changed from two-phase to one-phase with an increase in subphase temperature. This suggests that the mixed monolayer is assigned to the upper critical solution temperature type. The molecular aggregating behavior of the mixed monolayer was independent of the surface pressure for fatty acids in undissociated state, and also the monolayer phase of the single component system.
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