Ion beam induced liquid crystal alignment properties of 4-alkylphenoxymethyl-substituted polystyrenes

Hyo Kang, Byoung Har Hwang, Hong Koo Baik, Daeseung Kang, Jong Chan Lee

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The pretilt angles of liquid crystals (LCs) can be controlled over the range 0° to 90° using ion beam treated 4-alkylphenoxymethyl-substituted polystyrene films as alignment layers, where the alkyl group is -(CH2)nH (n = 1, 2 or 4), by changing the ion beam irradiation time, incidence angle and energy. In general, LC cells made using a polymer film with a longer irradiation time, higher irradiation incidence angle with respect to the planar direction and higher irradiation energy exhibited lower pretilt angles relative to the planar direction. Furthermore, the LC cells produced using polymer films containing longer alkyl groups and a higher molar content of 4-alkylphenoxymethyl side groups exhibited greater pretilt angles under similar irradiation conditions. The LC alignment behaviour demonstrated good correlation with the wettability of the polymer films, due to fragmentation of the side groups on the polymer surfaces during ion beam irradiation. The electro-optical characteristics of the LC cells formed using these polymer films were similar to those produced using rubbed polyimide films, which are the LC alignment layers most commonly encountered.

Original languageEnglish
Pages (from-to)179-187
Number of pages9
JournalLiquid Crystals
Volume37
Issue number2
DOIs
Publication statusPublished - 2010 Feb 1

Fingerprint

Liquid Crystals
Polystyrenes
Liquid crystals
Ion beams
polystyrene
ion beams
liquid crystals
alignment
Irradiation
Polymer films
irradiation
polymers
incidence
cells
wettability
polyimides
Polyimides
Wetting
Polymers
fragmentation

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Kang, Hyo ; Hwang, Byoung Har ; Baik, Hong Koo ; Kang, Daeseung ; Lee, Jong Chan. / Ion beam induced liquid crystal alignment properties of 4-alkylphenoxymethyl-substituted polystyrenes. In: Liquid Crystals. 2010 ; Vol. 37, No. 2. pp. 179-187.
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Ion beam induced liquid crystal alignment properties of 4-alkylphenoxymethyl-substituted polystyrenes. / Kang, Hyo; Hwang, Byoung Har; Baik, Hong Koo; Kang, Daeseung; Lee, Jong Chan.

In: Liquid Crystals, Vol. 37, No. 2, 01.02.2010, p. 179-187.

Research output: Contribution to journalArticle

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