Journal of the Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회논문지)

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Effects of Surface Order Parameter on Polar Anchoring Energy in NLC on Weakly Rubbed Polyimide Surface

  • Seo, Dae-Shik (Dept.of Electronics Engineering, Soongsil University)
  • Published : 1998.12.01
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Abstract

We have investigated the relationship between the polar anchoring energy and the surface order parameter in nematic liquid crystal (NLC), 4-n-pentyl-4-cyanobiphenyl (5CB), on the two kinds of the weakly rubbed polyimide (PI) surfaces. The observed polar anchoring energy of 5CB is approximately 2${\times}10^{-4}(J/m^2$) and then increases with increasing the rubbing strength (RS) on weakly rubbed surface (RS=57mm) with side chain at $30^{\circ}C$; same results are obtained on weakly rubbed PI surface without side chain. The surface order parameter of 5CB on rubbed PI surfaces increases with increasing the RS at a weak rubbing region. The surface order parameter of 5CB is strongly related to the characteristics of PI material. Consequently, we suggest that the polar anchoring energy of NLC is strongly attributed to the surface order parameter on rubbed PI surfaces.

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References

  1. Cryst. Liq. Cryst. v.165 Surface anchoring of nematic liquid crystals H. Yokoyama
  2. J.Appl.Phys. v.57 Novel method for determining the anchoring energy function at a nematic liquid crystal-wall interface from director distortions at high fields H. Yokoyama;H.A. van Sprang
  3. Appl. Phys. Lett. v.61 Temperature dependence of the polar anchoring strength of weakly rubbed polyimide films for the nematic liquid crystal (5CB) D.-S. Seo;Y. Iimura;S. Kobayashi
  4. J. Appl. Phys. v.33 Effects of conjugation of mesogenic core of nematic liquid crystals for polar anchoring energy and surface order parameter on rubbed polyimide films D.-S. Seo;N. Yoshida;S. Kobayashi;M. Nishikawa;Y. Yabe
  5. Appl. Phys. Lett. v.66 Effect of high pretilt angle for anchoring strength in nematic liquid crystal on rubbed polyimide surface containing trifluoromethyl moieties D.-S. Seo;S. Kobayashi
  6. J. Appl. Phys. v.34 Effects of rubbing and temperature dependence of polar anchoring strength of homogeneosly aligned nematic liquid crystal on polyimide Langmuir-Blodgett orientation films D.-S. Seo;S. Kobayashi;D. Y. Kang;H. Yokoyama
  7. Appl. Phys. Lett. v.66 Odd-even effects of the polar anchoring strength in nematic liquid crystal on rubbed polyimide Langmuir-Blodgett films with alkyl chain lengths D.-S. Seo;S. Kobayashi;M. Nishikawa;J. H. Kim;Y. Yabe
  8. Cryst. Liq. Cryst. v.213 generation of pretilt angle in nematic liquid crystal, 5CB, media aligned polyimide films prepared by spin-coating and LB techniques:effect of rubbing D.-S. Seo;K. Muroi;S. Kobayashi
  9. Appl.Phys.Lett. v.61 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 D.-S.Seo;S.Kobayashi;M.Nishikawa
  10. J. Chem. Phys. v.71 Surface-induced ordering of a liquid crystal in the isotropic phase K. Miyano