Large assembly formation via a two-step process in a chromonic liquid crystal.
Journal Article (Journal Article)
IR-806 is a near-infrared cyanine dye that forms assemblies in aqueous solutions which in turn orientationally order into a liquid crystal phase at concentrations as low as 0.5 wt %. Unlike many chromonic liquid crystals, the absorption spectrum of IR-806 changes dramatically with concentration, showing an isodesmic assembly process at lower concentrations followed by a second process at higher concentrations that is not isodesmic. The lower concentration assembly process is characterized by a free energy change per molecule of about 9 k(B)T, not unlike other chromonic systems. However, X-ray scattering measurements suggest that the assemblies that form during the higher concentration process are much larger than what is observed for many chromonic liquid crystals. Although there is a transitional region between the liquid crystal and isotropic phases of 10-15 °C, unlike most chromonic liquid crystals, no biphasic region is observed using polarizing microscopy.
Full Text
Duke Authors
Cited Authors
- Mills, EA; Regan, MH; Stanic, V; Collings, PJ
Published Date
- November 2012
Published In
Volume / Issue
- 116 / 45
Start / End Page
- 13506 - 13515
PubMed ID
- 23092355
Electronic International Standard Serial Number (EISSN)
- 1520-5207
International Standard Serial Number (ISSN)
- 1520-6106
Digital Object Identifier (DOI)
- 10.1021/jp306135w
Language
- eng