Study of the pretilt angle for 5CB on rubbed polyimide films containing trifluoromethyl moiety and analysis of the surface atomic concentration of F/C(%) with an electron spectroscope for chemical analysis

Dae-Shik Seo, Shunsuke Kobayashi, Michinori Nishikawa

Research output: Contribution to journalArticle

182 Citations (Scopus)

Abstract

The authors discuss the generation of pretilt angles for nematic liquid crystal (5CB) aligned on rubbed polyimide (PI) films containing trifluoromethyl. They also consider the the surface atomic concentration of fluorine (F) relative to that of carbon (C), F/C(%) with an electron spectroscopy for chemical analysis (ESCA) method in the shallow surface region at the depth of 3 and 12 nm as a function of rubbing strength (RS). PI films containing trifluorethyl moities were coated on indium-tin-oxide coated glass substrates by spin coating, and were polymidized thermally. It is shown that the fluorine concentration relative to the carbon atoms is rich in the shallow surface region of the unrubbed PI with the generated pretilt angle for weak rubbing being very large.. The generated pretilt angles and the conentration of the F atoms decrease with RS. A high pretilt angle at a low RS may be caused by van der Waals (VDW) dispersion interaction between the liquid crystal (LC) and the substrate which has a low surface energy. Medium and low pretilt angle at higher RS may be due to a combination of VDW dispersion force and steric interaction between the LC and the repeated asymmetric triangular structure formed by rubbing.

Original languageEnglish
Pages (from-to)2392-2394
Number of pages3
JournalApplied Physics Letters
Volume61
Issue number20
DOIs
Publication statusPublished - 1992 Nov 1

Fingerprint

chemical analysis
polyimides
spectrometers
liquid crystals
electrons
fluorine
carbon
high strength
indium oxides
tin oxides
surface energy
electron spectroscopy
atoms
coating
interactions
glass

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

Cite this

@article{b508ef5693a54ecf95d471e40739d5ad,
title = "Study of the pretilt angle for 5CB on rubbed polyimide films containing trifluoromethyl moiety and analysis of the surface atomic concentration of F/C({\%}) with an electron spectroscope for chemical analysis",
abstract = "The authors discuss the generation of pretilt angles for nematic liquid crystal (5CB) aligned on rubbed polyimide (PI) films containing trifluoromethyl. They also consider the the surface atomic concentration of fluorine (F) relative to that of carbon (C), F/C({\%}) with an electron spectroscopy for chemical analysis (ESCA) method in the shallow surface region at the depth of 3 and 12 nm as a function of rubbing strength (RS). PI films containing trifluorethyl moities were coated on indium-tin-oxide coated glass substrates by spin coating, and were polymidized thermally. It is shown that the fluorine concentration relative to the carbon atoms is rich in the shallow surface region of the unrubbed PI with the generated pretilt angle for weak rubbing being very large.. The generated pretilt angles and the conentration of the F atoms decrease with RS. A high pretilt angle at a low RS may be caused by van der Waals (VDW) dispersion interaction between the liquid crystal (LC) and the substrate which has a low surface energy. Medium and low pretilt angle at higher RS may be due to a combination of VDW dispersion force and steric interaction between the LC and the repeated asymmetric triangular structure formed by rubbing.",
author = "Dae-Shik Seo and Shunsuke Kobayashi and Michinori Nishikawa",
year = "1992",
month = "11",
day = "1",
doi = "10.1063/1.108174",
language = "English",
volume = "61",
pages = "2392--2394",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "20",

}

TY - JOUR

T1 - Study of the pretilt angle for 5CB on rubbed polyimide films containing trifluoromethyl moiety and analysis of the surface atomic concentration of F/C(%) with an electron spectroscope for chemical analysis

AU - Seo, Dae-Shik

AU - Kobayashi, Shunsuke

AU - Nishikawa, Michinori

PY - 1992/11/1

Y1 - 1992/11/1

N2 - The authors discuss the generation of pretilt angles for nematic liquid crystal (5CB) aligned on rubbed polyimide (PI) films containing trifluoromethyl. They also consider the the surface atomic concentration of fluorine (F) relative to that of carbon (C), F/C(%) with an electron spectroscopy for chemical analysis (ESCA) method in the shallow surface region at the depth of 3 and 12 nm as a function of rubbing strength (RS). PI films containing trifluorethyl moities were coated on indium-tin-oxide coated glass substrates by spin coating, and were polymidized thermally. It is shown that the fluorine concentration relative to the carbon atoms is rich in the shallow surface region of the unrubbed PI with the generated pretilt angle for weak rubbing being very large.. The generated pretilt angles and the conentration of the F atoms decrease with RS. A high pretilt angle at a low RS may be caused by van der Waals (VDW) dispersion interaction between the liquid crystal (LC) and the substrate which has a low surface energy. Medium and low pretilt angle at higher RS may be due to a combination of VDW dispersion force and steric interaction between the LC and the repeated asymmetric triangular structure formed by rubbing.

AB - The authors discuss the generation of pretilt angles for nematic liquid crystal (5CB) aligned on rubbed polyimide (PI) films containing trifluoromethyl. They also consider the the surface atomic concentration of fluorine (F) relative to that of carbon (C), F/C(%) with an electron spectroscopy for chemical analysis (ESCA) method in the shallow surface region at the depth of 3 and 12 nm as a function of rubbing strength (RS). PI films containing trifluorethyl moities were coated on indium-tin-oxide coated glass substrates by spin coating, and were polymidized thermally. It is shown that the fluorine concentration relative to the carbon atoms is rich in the shallow surface region of the unrubbed PI with the generated pretilt angle for weak rubbing being very large.. The generated pretilt angles and the conentration of the F atoms decrease with RS. A high pretilt angle at a low RS may be caused by van der Waals (VDW) dispersion interaction between the liquid crystal (LC) and the substrate which has a low surface energy. Medium and low pretilt angle at higher RS may be due to a combination of VDW dispersion force and steric interaction between the LC and the repeated asymmetric triangular structure formed by rubbing.

UR - http://www.scopus.com/inward/record.url?scp=0026943863&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026943863&partnerID=8YFLogxK

U2 - 10.1063/1.108174

DO - 10.1063/1.108174

M3 - Article

VL - 61

SP - 2392

EP - 2394

JO - Applied Physics Letters

JF - Applied Physics Letters

SN - 0003-6951

IS - 20

ER -