| 학회 |
한국고분자학회 |
| 학술대회 |
2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 |
29권 2호, p.19 |
| 발표분야 |
고분자 구조 및 물성 |
| 제목 |
Detailed Investigation on Factors Governing Liquid Crystal Alignment on Rubbed Polystyrene Films |
| 초록 |
The molecular reorientations and surface morphologies of rubbed films formed from atactic polystyrene (PS) samples with various molecular weights (Mw:weight-average molecular weight) were investigated in detail by atomic force microscopy, optical retardation analysis, and linearly polarized infrared spectroscopy. We have first discovered previously unknown surface topography features in rubbed films of PS with Mw＞9,800 : submicroscale groove-like meandering structures composed of fine-grooves like pebbles in tens nanometers are present, oriented perpendicular to the rubbing direction. The unusual surface morphology is a significant departure from the surface topographies observed so far for rubbed PS and other polymer films, for which grooves are usually only found parallel to the rubbing direction. On all the rubbed PS films, the vinyl main chains, however, were preferentially reoriented along the rubbing direction and the planes of the phenyl side groups were preferentially reoriented perpendicular to the rubbing direction with para-directions that were positioned nearly normal to the film plane. Nematic liquid crystal (LC) molecules were found to always align on the rubbed PS surfaces along the orientation direction of the submicroscale grooves generated by rubbing. We conclude that the alignment of LCs with only weak molecular interactions with rubbed PS film surfaces is governed by their interactions with the submicroscale grooves in cooperation with one of the two other important interactions, those with the reoriented main chain segments and those with the reoriented side groups. |
| 저자 |
함석규1, 이택준2, 이승우3, 윤진환4, 장태현5, 이문호6
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| 소속 |
1포항공대 / Department of Chemistry, 2Center for Integrated Molecular Systems, 3Division of Molecular and Life Sciences, 4BK21 Program, 5and Polymer Research Institute, 6Pohang Univ. of Science and Technology |
| 키워드 |
polystyrene; rubbing; submicroscale groove; moleular reorientation; liquid crystal alignment
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| E-Mail |
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