"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

Mechanism of homeotropic alignment of a doped liquid crystal

T. BEICA1, R. MOLDOVAN2,* , I. ZGURA1, S. FRUNZA1, M. POTERASU1

Affiliation

  1. National Institute for Materials Physics, PO Box Mg-07, Magurele, R-77125, Romania
  2. Romanian Academy Centre of Advanced Studies in Physics, Bucharest, Calea 13 Septembrie no.13, Romania

Abstract

In the paper, the physico-chemical orientation mechanism on solid surfaces for a liquid crystal (NP5 from Merck) doped for homeotropic alignment, is tested. For that, the dispersion and polar parts of surface tension of the liquid crystal are determined. Using substrates with and without adsorbed surfactant, the dispersion and polar parts of the surface tension of the substrates were also measured. Comparison of liquid and solid surface tensions, involved in the physico-chemical mechanism, failed to explain the difference of the molecular alignment for the two substrates. In the presence of the surfactant adsorbed on the surface, the steric model probably gives the explanation for the homeotropic alignment..

Keywords

Liquid crystals, Surface tension, Alignment.

Submitted at: May 22, 2006
Accepted at: July 20, 2006

Citation

T. BEICA, R. MOLDOVAN, I. ZGURA, S. FRUNZA, M. POTERASU, Mechanism of homeotropic alignment of a doped liquid crystal, Journal of Optoelectronics and Advanced Materials Vol. 8, Iss. 4, pp. 1512-1515 (2006)