Liquid Crystal Polymer Networks: Preparation, Properties, and Applications of Films with Patterned Molecular Alignment
- 22 April 2014
- journal article
- review article
- Published by American Chemical Society (ACS) in Langmuir
- Vol. 30 (45), 13499-13509
- https://doi.org/10.1021/la500454d
Abstract
Monolithically ordered liquid crystal polymer networks are formed by the photoinitiated polymerization of multifunctional liquid crystal monomers. This paper describes the relevant principles and methods, the basic structure–property relationships in terms of mesogenic properties of the monomers, and the mechanical and optical properties of the polymers. Strategies are discussed to control the molecular orientation by various means and in all three dimensions. The versatility of the process is demonstrated by two examples of films with a patterned molecular order. It is shown that patterned retarders can be made by a two-step polymerization process which is successfully employed in a transflective display principle. A transflective display is a liquid crystal display that operates in both a reflective mode using ambient light and a transmissive mode with light coming from a backlight system. Furthermore, a method is discussed to create a patterned film in a single polymerization process. This film has alternating planar chiral nematic areas next to perpendicularly oriented (so-called homeotropic) areas. When applied as a coating to a substrate, the film changes its surface texture. During exposure to UV light, it switches from a flat to a corrugated state.This publication has 40 references indexed in Scilit:
- Optical structure for a three-dimensional liquid-crystal cell using a wide-band and wide-view half-wave retarderJournal of the Korean Physical Society, 2013
- Cholesteric Liquid Crystals with a Broad Light Reflection BandAdvanced Materials, 2012
- Light-Induced Formation of Dynamic and Permanent Surface Topologies in Chiral–Nematic Polymer NetworksMacromolecules, 2012
- 3D structures using surface relief gratings of azobenzene materialsJournal of Optics A: Pure and Applied Optics, 2008
- Thermo-Mechanical Responses of Liquid-Crystal Networks with a Splayed Molecular OrganizationAdvanced Functional Materials, 2005
- Directed bending of a polymer film by lightNature, 2003
- 8.1: Novel High Performance Transflective LCD with a Patterned RetarderSID Symposium Digest of Technical Papers, 2003
- Synthesis and photopolymerization of cholesteric liquid crystalline diacrylatesLiquid Crystals, 1995
- Anisotropic thermal expansion of densely cross‐linked oriented polymer networksPolymer Engineering & Science, 1991
- Three-dimensionally ordered polymer networks with a helicoidal structureMacromolecules, 1990