2013 Fiscal Year Final Research Report
Adsorption of 3D Gel Networks on Solid Surfaces
| Project/Area Number |
24655092
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| Research Category |
Grant-in-Aid for Challenging Exploratory Research
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| Allocation Type | Single-year Grants |
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| Research Field |
Polymer chemistry
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| Research Institution | Yamagata University |
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Principal Investigator |
SANO Masahito 山形大学, 理工学研究科, 教授 (40344816)
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| Project Period (FY) |
2012-04-01 – 2014-03-31
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| Keywords | 高分子薄膜・表面 |
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| Research Abstract |
The contact angle of a drop of gelling solution on a flat solid surface was monitored as the hot solution was allowed to cool. When a solvent with a high cohesive energy and a wettable solid surface were used, a wetting solution turned into a dewetting solid at the gelation transition. The density profiles in gel as probed by confocal Raman microscopy reveal that adsorption of both gelator and solvent shifts at the transition and the solvent is severely depleted from the interfacial region. Thus, the wetting reversal is accompanied by the interfacial desolvation. As a result of the adsorption shift during gelation process in progress, a locally concentrated region of the gelator is frozen in space far away from the surface. This is a thermodynamically unstable state, but can be realized reproducibly. The profile analysis also shows that the effect of surface extends out to a few hundred micrometers, two orders of magnitude larger than the bulk correlation length.
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