2006 Fiscal Year Final Research Report Summary
Control and enhancement of liquid crystal alignment by surface modification of polymer film
| Project/Area Number |
17560019
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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 |
Thin film/Surface and interfacial physical properties
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| Research Institution | AKITA UNIVERSITY |
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Principal Investigator |
YAMAGUCHI Rumiko AKITA UNIVERSITY, Faculty of Engineering and Resource Science, associate professor, 工学資源学部, 助教授 (30170799)
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| Project Period (FY) |
2005 – 2006
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| Keywords | liquid Crystal / alignment surface / polymer / surface modification / crosslinking reaction / multidomain alignment / latent image / optical security device |
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| Research Abstract |
(1) The uniformly rubbed polyvinyl cinnamate (PVCi) surface is irradiated with nonpolarized UV light to increase the anchoring energy. The uniformly rubbed polyimide (PI) surface with strong anchoring is prepared as a counter alignment substrate. When the easy axes of the two substrates are perpendicular, LC molecules twist at about 90° on the PVCi surface irradiated with UV light. On the other hand, the homogeneous orientation is observed on the surface without the UV irradiation, since the anchoring is too weak to form twisted orientation. The continuous grey scale image is also fabricated. The cell filled with the LC is exposed with the UV light through a negative film, and is thermally developed and fixed.
(2) I have studied LC alignment surface which has two orthogonal easy axes induced by a unidirectional rubbing treatment. When the photo-reactive polymer with chalconyl side chains is irradiated with non-polarized UV light and subsequently rubbed with a cloth, LCs align parallel and perpendicular to the rubbing direction on the UV irradiated and non-irradiated surfaces, respectively. The micro patterning of the LC alignment is successfully demonstrated through the simple process using a photo mask and non-polarized UV irradiation technique. Plasma surface modification and rubbing treatment are also carried out on a polymer film to change the liquid crystal alignment properties. The same result is obtained as a photo-modification.
(3) The latent images can be optically and thermally written on the cell. In addition, the guest-host LC cell which has dual latent images is successfully demonstrated. Those images are visualized when using one or two polarizers. Such a multiple alignment process is very simple and suitable for both large and small area patterning with a high spatial resolution. Therefore, patterned LC cells have a grate advantage of the application to optical security devices.
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Research Products
(25 results)
