광감성 폴리비닐플루오로신나메이트의 액정 배향에 관한 연구

김동수; 안원술; 하기룡; O.Buluy; Yu.Reznikov; DongSoo Kim; WonSool Ahn; KiRyong Ha; O. Buluy; Yu. Reznikov

Polymer(Korea), Vol.31, No.5, 393-398, September, 2007

Export Citation

광감성 폴리비닐플루오로신나메이트의 액정 배향에 관한 연구

Studies of Liquid Crystal Alignment on the Photosensitive Polyvinylfluorocinnamate

김동수, 안원술 , 하기룡 ^†, O.Buluy¹, Yu.Reznikov¹

계명대학교 화학공학과
¹National Academy of Sciences of Ukraine Institute of Physics

DongSoo Kim, WonSool Ahn , KiRyong Ha^†, O. Buluy¹, and Yu. Reznikov¹

Department of Chemical Engineering, Keimyung University, Dalseo-gu, Daegu 704-701, Korea
¹Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauki 46, Kyiv 03039, Ukraine

E-mail:

초록

편광 푸리에 변환 적외선 분광법(polarized fourier transform infrared spectroscopy)과 자외선 분광법(ultraviolet spectroscopy)을 이용하여 액정 디스플레이(liquid crystal display, LCD)의 배향막으로 사용가능한 polyvinylfluorocinnamate(PVCN-F) 필름의 편광 자외선(polarized UV, PUV) 조사 및 러빙에 따른 액정의 배향 메커니즘에 관한 연구를 수행하였다. UV의 조사시간이 증가함에 따라 PVCN-F cinnamoyl group의 C＝C기들의 cycloaddition 반응으로 인하여 1638 cm-1에서 나타나는 vinylene -C＝C- FT-IR 흡수 피크들의 면적이 감소하고, 1712 cm-1에서 나타나는 conjugated C＝O 신축진동에 의한 피크가 nonconjugated C＝O 신축진동 피크인 1734 cm-1로 이동함을 확인하였다. 또한 PUV가 조사된 PVCN-F 배향막을 사용하여 제조된 액정 셀에서는 조사된 PUV의 극성 방향과 수직으로 액정이 배향함을 확인하였고, 러빙 방법으로 제조된 PVCN-F 배향막을 사용한 액정 셀에서는 액정이 러빙 방향과 수평으로 배향됨을 dichroic dye(이색성 염료)의 첨가 없이 편광 FT-IR 스팩트럼을 사용하여 확인하였다.

We studied the mechanism of liquid crystal alignment on polyvinylfluorocinnamate (PVCN-F) films which were irradiated by UV using polarized fourier transform infrared (FT-IR) spectroscopy and ultraviolet/visible (UV/Vis) spectroscopy. UV irradiation of PVCN-F films caused decrease of vinylene -C＝C- stretching peak area at 1638 cm-1 and shift of conjugated C＝O stretching vibration at 1712 cm-1 to 1734 cm-1 which is caused by nonconjugated C＝O stretching vibration. To study the orientation direction of 5CB liquid crystal(LC) molecules in the liquid crystal cell with PUV irradiation, rubbing treatment or without any treatment on the PVCN-F alignment layer, we used polarized FT-IR dichroism technique. We successfully measured 5CB LC alignment directions, which are perpendicular to the irradiated PUV polarization direction and parallel to the rubbing direction in the liquid crystal cell without using dichroic dyes.

Keywords:photoalingment;polyvinylfluorocinnamate;FT-IR;liquid crystal;dichroism technique

[References]

Ych P, Gu C, Optics of Liquid Crystal Displays, John Wiley & Sons, Inc, New York, p.35 (1999)
Lim JC, Choi SH, Kim W, Kim SS, Song K, Polym.(Korea), 29(4), 413 (2005)
Park WS, US Patent 5538823 (1996)
Lee BH, Ham SK, Lim JC, Song K, Polym.(Korea), 21(6), 1059 (1997)
Chae B, Lee SW, Ree M, Jung YM, Kim SB, Langmuir, 19(3), 687 (2003)
Demus D, Richter L, Textures of Liquid Crystals, Verlag Chemie, New York, p. 32 (1978)
Sakamoto K, Arafune R, Ito N, Ushioda S, Suzuki Y, Morokawa S, J. Appl. Phys., 100, 124 (1996)
Gomez EH, Barrera FN, Neira JL, Biophys. Chem., 115, 229 (2005)
Farrell HM, Wickham JED, Unruh JJ, Qi PX, Hoagland PD, Food Hydrocolloids, 15, 341 (2001)
Kim IH, Kim WS, Ha K, Polym.(Korea), 26(4), 431 (2002)
Kawatsuki N, Takatsuka H, Kawakami Y, Yamamoto T, Polym. Adv. Technol., 10, 429 (1999)
Wu S, Appl. Optics, 26, 3434 (1987)
Ha K, West JL, Mol. Cryst. Liq. Cryst., 325, 13 (1998)

[Referenced By]

[Related Articles]

[1] Ych P, Gu C, Optics of Liquid Crystal Displays, John Wiley & Sons, Inc, New York, p.35 (1999)

[2] Lim JC, Choi SH, Kim W, Kim SS, Song K, Polym.(Korea), 29(4), 413 (2005)

[3] Park WS, US Patent 5538823 (1996)

[4] Lee BH, Ham SK, Lim JC, Song K, Polym.(Korea), 21(6), 1059 (1997)

[5] Chae B, Lee SW, Ree M, Jung YM, Kim SB, Langmuir, 19(3), 687 (2003)

[6] Demus D, Richter L, Textures of Liquid Crystals, Verlag Chemie, New York, p. 32 (1978)

[7] Sakamoto K, Arafune R, Ito N, Ushioda S, Suzuki Y, Morokawa S, J. Appl. Phys., 100, 124 (1996)

[8] Gomez EH, Barrera FN, Neira JL, Biophys. Chem., 115, 229 (2005)

[9] Farrell HM, Wickham JED, Unruh JJ, Qi PX, Hoagland PD, Food Hydrocolloids, 15, 341 (2001)

[10] Kim IH, Kim WS, Ha K, Polym.(Korea), 26(4), 431 (2002)

[11] Kawatsuki N, Takatsuka H, Kawakami Y, Yamamoto T, Polym. Adv. Technol., 10, 429 (1999)

[12] Wu S, Appl. Optics, 26, 3434 (1987)

[13] Ha K, West JL, Mol. Cryst. Liq. Cryst., 325, 13 (1998)