Control of periodic defect arrays of 8CB (4′-n-octyl-4-cyano-biphenyl) liquid crystals by multi-directional rubbing

被引：24

作者：

Ok, Jong Min ^{[1
]}

Kim, Yun Ho ^{[2
]}

Jeong, Hyeon Su ^{[3
]}

Yoo, Hae-Wook ^{[1
]}

Kim, Jung Hyun ^{[4
]}

Srinivasarao, Mohan ^{[5
,6
]}

Jung, Hee-Tae ^{[1
]}

机构：

[1] Korea Adv Inst Sci & Technol, Dept Chem & Biomol Engn, Taejon 305701, South Korea

[2] Korea Res Inst Chem Technol, Adv Funct Mat Grp, Dajeon 305600, South Korea

[3] SK Innovat, Mat R&D Ctr, Opt Mat Lab, Taejon 305712, South Korea

[4] LG Chem Ltd, IT&E Mat R&D, Taejon 305380, South Korea

[5] Georgia Inst Technol, Sch Chem & Biochem, Sch Mat Sci & Engn, Atlanta, GA 30332 USA

[6] Korea Adv Inst Sci & Technol, Dept Chem & Biomol Engn, World Class Univ Program, Taejon 305701, South Korea

来源：

SOFT MATTER | 2013年 / 9卷 / 42期

基金：

新加坡国家研究基金会;

关键词：

FOCAL CONIC DOMAINS; BLOCK-COPOLYMERS; ORDERED PATTERNS; PRETILT ANGLE; ALIGNMENT; SURFACE; FILMS; GRAPHOEPITAXY; LITHOGRAPHY; FABRICATION;

D O I：

10.1039/c3sm52008k

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

In this study, we introduce a simple multi-directional rubbing method to generate various periodic patterns of toric focal conic domains (TFCDs), a typical smectic (Sm) LC defect by using the commonly used Sm LC materials, 4'-n-octyl-4-cyano-biphenyl (8CB). We have successfully obtained a variety of spatially arranged TFCD arrays such as parallelogrammic, hexagonal and square arrays by changing the rubbing angle (Omega) between two different rubbing directions. Our experimental results demonstrate that frustration and distortion of nematic LC molecules at the intersections act as effective seeds to help positioning of TFCDs. Furthermore, the existence of nematic-Smectic A (SmA) phase transition is quite important in controlling the arrangement of TFCDs as the alignment of the nematic director strongly influences the arrangement of TFCDs formed in the SmA phase.

引用

页码：10135 / 10140

页数：6

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