Director Orientation of Nematic Side-Chain Liquid Crystalline Polymers Under Shear Flow: Comparison of a Flow-Aligning and a Non-Flow-Aligning Polysiloxane
✍ Scribed by Hartmut Siebert; Isabel Quijada-Garrido; Jan Vermant; Laurence Noirez; Wesley R. Burghardt; Claudia Schmidt
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 472 KB
- Volume
- 208
- Category
- Article
- ISSN
- 1022-1352
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
The flow behavior and phase structure of two side‐chain liquid‐crystalline polysiloxanes with the same mesogens but different spacers of either four (PSi4) or six (PSi6) methylene groups are studied in the nematic phase by ^2^H NMR, polarization microscopy, and scattering of light, neutrons, and X‐rays. PSi4 is flow‐aligning, forming a monodomain with the director close to the flow direction, whereas PSi6 is non‐flow‐aligning showing a polydomain structure with a preferred director orientation corresponding to the log‐rolling state. The flow behavior of PSi6 is related to the presence of strong smectic clusters. The director tilt in the smectic clusters of both polymers is reported.
magnified image