Autor: |
Mann, Ian, Xinfei Yu, Wen-Bin Zhang, Van Horn, Ryan M., Ge, Jason J., Graham, Matthew J., Harris, Frank W., Cheng, Stephen Z. D. |
Předmět: |
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Zdroj: |
Chinese Journal of Polymer Science (Springer Science & Business Media B.V.); Jan2011, Vol. 29 Issue 1, p81-86, 6p, 1 Black and White Photograph, 1 Diagram, 2 Graphs |
Abstrakt: |
The polymer surface relaxation in thin films has been a long debating issue. We report a new method on studying surface relaxation behaviors of polymer thin films on a solid substrate. This method involved utilizing a rubbed polyimide surface with a pretilting angle in a liquid crystalline cell. Due to the surface alignment, the liquid crystals were aligned along the rubbing direction. During heating the liquid crystalline cell, we continuously monitored the change of orientation of the liquid crystals. It is understood that at a temperature where the orientation of liquid crystal is lost, the surface relaxation on the glass substrate takes place to lose the polyimide surface orientation. It was found that the relaxation temperature at which the liquid crystals lose their orientation depends on the film thickness of the polyimide. A quantitative linear relationship between the relaxation temperature and reciprocal of the film thickness can be observed. Furthermore, different topologies of the rubbed and relaxed thin films were amplified using the polyethylene decoration method and observed using atomic force microscopy. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
Externí odkaz: |
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