Abstract
Rubbing-induced molecular alignment on an alkyl-branched polyimide film with varying unidirectional rubbing strength has been investigated with the use of optical phase retardation measurement, atomic force microscopy (AFM), and second-harmonic generation (SHG). Our AFM images suggest that the rubbing-induced micro-groove should play a minor role in aligning liquid crystal (LC) molecules. The polar angle of the polar head group of a LC monolayer on an alkyl-branched polyimide film was found to vary with the rubbing strength. The results obtained from various experimental techniques can be reconciled with a simple molecular model proposed in this paper.
Original language | English |
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Pages (from-to) | 77-84 |
Number of pages | 8 |
Journal | Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals |
Volume | 270 |
Issue number | 1 |
DOIs | |
State | Published - 1 Aug 1995 |
Keywords
- Liquid crystal
- alkyl-branched
- atomic force microscopy
- optical second-harmonic generation
- phase retardation
- polyimide
- pretilt angle