1997 Fiscal Year Final Research Report Summary
Coating Films of Liquid Crystalline polymers as Alignment Layrs
| Project/Area Number |
08455092
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Fluid engineering
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
NAKAMURA Kiyoji Faculty of Engineering, Osaka University, Professor, 工学部, 教授 (30029178)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Takehiro Faculty of Engineering, Osaka University, Assistant, 工学部, 助手 (40252621)
YASUDA Kazunori Faculty of Engineering, Osaka University, Assistant, 工学部, 助手 (80239756)
MORI Noriyasu Faculty of Engineering, Osaka University, Associate Prof., 工学部, 助教授 (30124069)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Keywords | Liquid crystalline polymers / Coating / Alignment layr / Numerical simulation / Doi model / Band texture / AFM / Morphology |
|---|
| Research Abstract |
We tried to develop a new alignment layr by using a coating film of luquid crystalline polymers. Aqueous solutions and ethanol solutions both in isotropic and liquid crystalline states were used as coating materials. Results obtained in the present work are as follows.
1. The ribbing phenomenon was occurred and its number per unit length increased with increasing velocity of coating and decreasing film thickness.
2. The band texture was observed in the thin films processed from the liquid crystalline solutions at high coating velocities.
3. The disclination line, which indicates that the molecules of liquid crystals align in a one direction on a coating film, was found in a droplet of 5CB placed on the coating film processed from isotropic solutions if the film is thin and the coating velocity is high. On the contrary, it was confirmed that the alignment state was random for thick films processed at low coating velocities.
4. The surface morphology of coating films was measured with an atomic force microscope (AFM). The micro ribs, which corresponded to the band texture, was found. Any structures, which induced the molecular alignment of 5CB,were not able to be specified in the other films.
5. In the numerical simulation of spinning flow of liquid crystalline polymers using the Doi model, molecules align parallel to the flow direction in the region close to the filament surface because of the elongational flow.
6. We concluded that the molecular alignment of 5CB on the films processed from the isotropic solutions was caused by the flow-induced alignment of HPC molecules fixed only in the vicinity of the film surface.
|
