Planar Alignment of Columnar Discotic Liquid Crystals by Isotropic Phase Dewetting on Chemically Patterned Surfaces

被引：37

作者：

Bramble, Jonathan P. ^{[1
]}

Tate, Daniel J. ^{[2
]}

Revill, Derek J. ^{[1
]}

Sheikh, Khizar H. ^{[1
]}

Henderson, James R. ^{[1
]}

Liu, Feng ^{[3
]}

Zeng, Xiangbing ^{[3
]}

Ungar, Goran ^{[3
,4
]}

Bushby, Richard J. ^{[2
]}

Evans, Stephen D. ^{[1
]}

机构：

[1] Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England

[2] Univ Leeds, Sch Chem, Ctr Mol Nanosci, Leeds LS2 9JT, W Yorkshire, England

[3] Univ Sheffield, Dept Mat Engn, Sheffield S1 3JD, S Yorkshire, England

[4] Seoul Natl Univ, WCU Chem Convergence Energy & Environm, Seoul 151744, South Korea

来源：

ADVANCED FUNCTIONAL MATERIALS | 2010年 / 20卷 / 06期

基金：

英国工程与自然科学研究理事会;

关键词：

HOMEOTROPIC ALIGNMENT; ORIENTATION; FILMS; SEMICONDUCTORS; TRANSPORT; GROWTH; ORDER;

D O I：

10.1002/adfm.200902140

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

A novel method of creating planar aligned columnar discotic liquid crystals (cDLCs) on surfaces, which also gives control over the azimuthal angle, is presented. Surfaces are chemically patterned with stripes via microcontact printing of organothiol self-assembled monolayers (SAMs) on gold, or via deep UV patterning of organosilane SAMs on silicon. These are then used to isolate long droplets of cDLCs by dewetting in the isotropic phase. Upon cooling from the isotropic into the hexagonal columnar phase, polarizing microscopy reveals that the cDLC aligns in a planar orientation. Results for three triphenylene derivatives (HAT-6; HHTT, H7T) and for a phthalocyanine derivative (8H(2)Pc) are presented. H7T and HAT-6 are found to align with the director perpendicular to the stripe direction, but HHTT and 8H(2)Pc align parallel to the stripe direction. This relatively simple new method for creating planar aligned columnar phases of DLCs gives control over the azimuthal angle: a condition required for organic field-effect transistor applications of cDLCs.

引用

页码：914 / 920

页数：7

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