Liquid crystal alignment capability on polyimide Langmuir-Blodgett surfaces with alkyl chain lengths

D. S. Seo, S. Kobayashi

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The liquid crystal (LC) alignment capability in 4-n-pentyl-4′-cyanobiphenyl (5CB) on polyimide (PI) Langmuir-Blodgett (LB) surface with alkyl chain lengths was investigated. The pretilt angle of 5CB increased by unidirectional rubbing treatment on PI-LB surface. The induced optical retardation on PI-LB surface increased by the rubbing. The extrapolation length de of 5CB for rubbed PI-LB surfaces with even-number is small, compared with odd-number near the clearing temperature Tc. The extrapolation length de of 5CB with odd-number increases gradually as the temperature increases but it tends to diverge near the Tc. Therefore the polar anchoring strength with even-number is strong because of relatively high surface ordering caused by more crystalline surfaces. The anchoring energy of 5CB with alkyl chain length of 7 carbons is approximately 1 × 10-3 (J/m2); it indicates the strong anchoring strength. In consequences, we suggest that the LC align capability in NLC on PI-LB surface is strongly related to the characteristics of the polymer.

Original languageEnglish
Pages (from-to)1-10
Number of pages10
JournalMolecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals
Volume339
DOIs
Publication statusPublished - 2000 Jan 1

Fingerprint

Liquid Crystals
Chain length
polyimides
Polyimides
Liquid crystals
liquid crystals
alignment
Extrapolation
extrapolation
clearing
Polymers
Carbon
Crystalline materials
Temperature
temperature
carbon
polymers

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this

@article{89caf50027084282bbcb09b6bf0ba759,
title = "Liquid crystal alignment capability on polyimide Langmuir-Blodgett surfaces with alkyl chain lengths",
abstract = "The liquid crystal (LC) alignment capability in 4-n-pentyl-4′-cyanobiphenyl (5CB) on polyimide (PI) Langmuir-Blodgett (LB) surface with alkyl chain lengths was investigated. The pretilt angle of 5CB increased by unidirectional rubbing treatment on PI-LB surface. The induced optical retardation on PI-LB surface increased by the rubbing. The extrapolation length de of 5CB for rubbed PI-LB surfaces with even-number is small, compared with odd-number near the clearing temperature Tc. The extrapolation length de of 5CB with odd-number increases gradually as the temperature increases but it tends to diverge near the Tc. Therefore the polar anchoring strength with even-number is strong because of relatively high surface ordering caused by more crystalline surfaces. The anchoring energy of 5CB with alkyl chain length of 7 carbons is approximately 1 × 10-3 (J/m2); it indicates the strong anchoring strength. In consequences, we suggest that the LC align capability in NLC on PI-LB surface is strongly related to the characteristics of the polymer.",
author = "Seo, {D. S.} and S. Kobayashi",
year = "2000",
month = "1",
day = "1",
doi = "10.1080/10587250008031028",
language = "English",
volume = "339",
pages = "1--10",
journal = "Molecular Crystals and Liquid Crystals",
issn = "1542-1406",
publisher = "Taylor and Francis Ltd.",

}

TY - JOUR

T1 - Liquid crystal alignment capability on polyimide Langmuir-Blodgett surfaces with alkyl chain lengths

AU - Seo, D. S.

AU - Kobayashi, S.

PY - 2000/1/1

Y1 - 2000/1/1

N2 - The liquid crystal (LC) alignment capability in 4-n-pentyl-4′-cyanobiphenyl (5CB) on polyimide (PI) Langmuir-Blodgett (LB) surface with alkyl chain lengths was investigated. The pretilt angle of 5CB increased by unidirectional rubbing treatment on PI-LB surface. The induced optical retardation on PI-LB surface increased by the rubbing. The extrapolation length de of 5CB for rubbed PI-LB surfaces with even-number is small, compared with odd-number near the clearing temperature Tc. The extrapolation length de of 5CB with odd-number increases gradually as the temperature increases but it tends to diverge near the Tc. Therefore the polar anchoring strength with even-number is strong because of relatively high surface ordering caused by more crystalline surfaces. The anchoring energy of 5CB with alkyl chain length of 7 carbons is approximately 1 × 10-3 (J/m2); it indicates the strong anchoring strength. In consequences, we suggest that the LC align capability in NLC on PI-LB surface is strongly related to the characteristics of the polymer.

AB - The liquid crystal (LC) alignment capability in 4-n-pentyl-4′-cyanobiphenyl (5CB) on polyimide (PI) Langmuir-Blodgett (LB) surface with alkyl chain lengths was investigated. The pretilt angle of 5CB increased by unidirectional rubbing treatment on PI-LB surface. The induced optical retardation on PI-LB surface increased by the rubbing. The extrapolation length de of 5CB for rubbed PI-LB surfaces with even-number is small, compared with odd-number near the clearing temperature Tc. The extrapolation length de of 5CB with odd-number increases gradually as the temperature increases but it tends to diverge near the Tc. Therefore the polar anchoring strength with even-number is strong because of relatively high surface ordering caused by more crystalline surfaces. The anchoring energy of 5CB with alkyl chain length of 7 carbons is approximately 1 × 10-3 (J/m2); it indicates the strong anchoring strength. In consequences, we suggest that the LC align capability in NLC on PI-LB surface is strongly related to the characteristics of the polymer.

UR - http://www.scopus.com/inward/record.url?scp=0033752041&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033752041&partnerID=8YFLogxK

U2 - 10.1080/10587250008031028

DO - 10.1080/10587250008031028

M3 - Article

VL - 339

SP - 1

EP - 10

JO - Molecular Crystals and Liquid Crystals

JF - Molecular Crystals and Liquid Crystals

SN - 1542-1406

ER -