Nonlinear optical studies of liquid crystal alignment on a rubbed polyvinyl alcohol surface

Citation
X. Wei et al., Nonlinear optical studies of liquid crystal alignment on a rubbed polyvinyl alcohol surface, PHYS REV E, 62(4), 2000, pp. 5160-5172
Citations number
50
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW E
ISSN journal
1063-651X → ACNP
Volume
62
Issue
4
Year of publication
2000
Part
A
Pages
5160 - 5172
Database
ISI
SICI code
1063-651X(200010)62:4<5160:NOSOLC>2.0.ZU;2-6
Abstract
Sum-frequency vibrational spectroscopy and second-harmonic generation have been used to measure the orientational distributions of the polymer chains and adsorbed 8CB liquid crystal molecules on a rubbed polyvinyl alcohol sur face. Results show that the polymer chains at the surface appear to be well aligned by rubbing, and the adsorbed liquid crystal molecules are aligned, in turn, by the surface polymer chains. Strong correlation exists between the orientational distributions of the polymer chains and the liquid crysta l molecules, indicating that the surface-induced bulk alignment of a liquid crystal film by rubbed polymer surfaces is via an orientational epitaxylik e mechanism.