ESR studies of aqueous cholesteric lyotropic liquid crystals

✍ Scribed by Bruce J. Forrest; Jairajh Mattai

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 427 KB
• Volume: 35
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(84)90027-6

✦ Synopsis

Cholesteric aqueous lyotropic liquid crystals have been prepared by the addition of optically active guest molecules to Type II disk micelles which orient in magnetic fields. ESR spectra obtained when the helical axis is perpendicular to the field direction are sensitive to the nematic-cholesteric transition when the overall pitch is quite long, indicating the presence of regions of cholestericity in a nematic matrix. Once an equilibrium twisted structure is formed, further changes in the pitch of the helix could not be detected by the spin probe. The results support an irregular distribution of micelles in the untwisted mesophase.