자기조립단분자막을 이용한 액정수직배향법 = Vertical Alignment Effect of Liquid Crystal by Using Self-assembled Monolayer

다국어 초록 (Multilingual Abstract)

We investigated vertical alignment (VA) effects of self-assembled monolayers depending on the anisotropy of the underlying inorganic surface. A hydrophobic SAM surface aligned the LC vertically, initially. When the underlying surface is anisotropic, the LC anchoring on the SAM surface produces the pretilt property. We observed a uniform LC alignment irrespective to alkyl chain lengths of SAM molecules. This means that the anisotropic surface modification of the underlying inorganic surface affects the VA effects of the SAM surface. However, the thermal stability of the SAM ordering and the resulting LC anchoring became better as the alkyl chain length of the SAM molecules is higher. As surface treatment methods to produce the anisotropic underlying surface for SAM ordering, we tested the mechanical rubbing method where we could achieve SAM ordering effects and the VA LC anchoring effects with pre-tilt. We expect the patterned VA mode can be simply prepared just by the SAM treatment on the conventional planar LC alignment surface if the surface is chemically available to the surface bonding of the SAM. Currently, we are making experiments on surface modification with the SAM to the ion-beam treated LC alignment surface to change LC anchoring from the planar anchoring to the homeotropic anchoring for the multi-domain VA surface.

목차 (Table of Contents)

• 1. 서론 1
• 2. 액정의 수직배향방법 및 이론 3
• 2.1 액정 배향 기본 개념 3
• 2.2 액정 배향법 6
• 2.2.1 러빙법 6
• 2.2.2 광배향법 10
• 2.2.3 이온빔 배향법 11
• 2.3 다중 수직배향 액정모드 13
• 3. 자기조립단분자막(Self-Assembled Monolayer : SAM) 16
• 3.1 SAM의 구조 및 특징 16
• 3.1.1 소수성과 친수성 19
• 3.1.2 ODTS의 구조 20
• 3.2 ODTS의 화학적 반응 21
• 4. SAM 분자 길이에 따른 배향특성 24
• 4.1 시편의 구조 및 액정 배향 계면 조건 24
• 4.2 러빙된 SAM에서의 액정 배향 29
• 4.3 러빙된 SiO2 기판 상에 형성된 SAM 계면상의 액정 배향 32
• 4.4 정량적 액정 배향 특성 분석 35
• 4.4.1 선경사각 측정 35
• 4.4.2 CV법에 의한 액정의 수직 배향력 측정 41
• 4.4.3 열적 안정성 측정 44
• 4.5 SAM 상의 액정 배향 원리 47
• 5. 결론 49
• 참고 문헌 50
• 영문 초록 54