- Author : Jung-Sheng Wu
- Publisher :
- Release : 2002
- ISBN :
- Pages : 213 pages
Surface Morphology and Ordering in Side chain Liquid Crystal Diblock and Homopolymer Ultrathin Films
Download or read book Surface Morphology and Ordering in Side chain Liquid Crystal Diblock and Homopolymer Ultrathin Films written by Jung-Sheng Wu and published by . This book was released on 2002 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Due to the wetting properties of the LC diblock copolymer, novel LC terraces were observed on the top surfaces corresponding to single smectic layer spacing. For diblock thin films, both blocks coexist at the air surfaces to form a mixed surface. Hybrid morphologies, consisting of both symmetrical and anti-symmetrical wettings, were noted for the lamellar morphology with film thicknesses between 0.5 and 1.5Lo. The surface properties are determined by LC orientation, which depends on the film thickness. Homeotropic anchoring of the smectic LC mesogens at the air interface was observed in both the homopolymer and the block copolymers, resulting in smectic terraces on the top surfaces of the films. In thicker films, when the influence of the substrate was decreased, the lamellar orientation was found to undergo a transition from parallel stacking near the substrate to perpendicular arrangement at the air surface. Effects of annealing and solvent exposure on the resulting thin-film behavior were also addressed.