Effect of the polymer tilt angle for generation of pretilt angle in nematic liquid crystal on rubbed polyimide surfaces

• Published in: Japanese Journal of Applied Physics Vol. 34; no. 4B; pp. L503 - L506
• Main Authors: DAE-SHIK SEO, ARAYA, K, YOSHIDA, N, NISHIKAWA, M, YABE, Y, KOBAYASHI, S
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 1995
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Liquid crystals; Orientational order of liquid crystals; electric and magnetic field effects on order; Physics; Structure of solids and liquids; crystallography; Organic polymers; Experimental study; Liquid crystals; Nematic crystals; Inclination; Substrates; Molecular orientation; Oriented polymer; Friction; Saturated aliphatic compound; Polyimides; Benzenic compound; Nitriles; Organic compounds
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/jjap.34.l503

We have studied the effect of the polymer tilt angle for pretilt angle generation in nematic liquid crystal, 4-cyano-4
′
-n-penthylbiphenyl (5CB) on rubbed polyimide surfaces. The polymer tilt angle was determined by measuring induced optical retardation produced in rubbed polyimide (PI) surfaces by rubbing. We suggest that the polymer tilt angle is not related directly to the pretilt angle on rubbed PI surfaces by rubbing. We proposed a microscopic model of pretilt angle generation on rubbed PI surfaces by rubbing. Finally, we conclude that the pretilt angle generation of 5CB strongly depends on the characterization of polymer materials and the micro-asymmetric triangular structure of the polymer on rubbed polyimide surfaces.