1998 Fiscal Year Final Research Report Summary
Surface Structure of Polymer Gels and Emerging Functions
| Project/Area Number |
09640684
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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 |
機能・物性・材料
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| Research Institution | Yokohama National University |
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Principal Investigator |
SUZUKI Atsushi Yokohama National University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (90162924)
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| Project Period (FY) |
1997 – 1998
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| Keywords | polymer gel / surface structure / volume phase transition / network inhomogeneity / static contact angle / hydrophobicity / surface roughness / characteristic length |
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| Research Abstract |
In this study, we investigated the mesoscopic surface structure of polymer gels (such as surface roughness and characteristic length) using an atomic force microscopy (AFM), as well as its role in determining the macroscopic functions (such as adhesion, surface tension, and friction).
1. Surface structure of poly(N-isopropylacrylamide) (NIPA) gels in water was studied using AFM, and it was established that the surface conformation is characterized by the sponge-like domains with submicrometer scale. We investigated the effect of the inhomogeneities of the bulk networks on the domain structure, as well as the effect of the temperature change. Surface roughness due to the sponge-like domains was discussed in terms of the auto-correlation function and of the power spectral density calculated from the topographies.
2. In order to discuss the relation between the surface roughness and the macroscopic surface properties, the static contact angle of sessile air bubbles in water was measured for NIPA gels as a model gel with hydrophobic interactions. The static contact angle versus temperature was found to depend on the inhomogeneities of the bulk networks. We showed that the static contact angle can be governed not only by the chemical (in the present case, the balance of the hydrophobic-hydrophilic interactions) but also by the physical properties of hydrophobic polymer gels in response to a temperature change. Of the various effective physical factors being considered, the following would be essential in determining the static contact angle : the polymer density, the surface roughness, and the network homogeneity.
We believe that the present study is of crucial importance for the future development and application of new technologies based on the basic concepts gained from the fundamental studies of polymer gel surfaces.
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Research Products
(8 results)
