ZB 10 - Soft Condensed Matter (R. Holyst)

Collective Rotations of Ferroelectric Liquid Crystals at the Air/Water Interface

Author(s): Milczarczyk-Piwowarczyk, Patrycja and Zywocinski, Andrzej and Noworyta, Krzysztof and Holyst, Robert
Title: Collective Rotations of Ferroelectric Liquid Crystals at the Air/Water Interface
Abstract: We study the Langmuir monolayers of four different ferroelectric liquid on water surface. Two of them are attached to water surface by polar groups, and the chiral groups, at the opposite ends of the molecules, remain well above the interface. The other two have both groups (polar and chiral) at close proximity, therefore the chiral group is also attached to the surface or even in water. We demonstrate that only when the chiral group of ferroelectric liquid crystal in Langmuir monolayer is not attached the interface and stays in the air does the system exhibit the rotations induced by evaporation of water (described for the time by: Tabe, Y.; Yokoyama, H. Nat. Mater. 2003, 2, 806). The of surface pressure and surface potential versus molecular of four compounds were measured with simultaneous observations Brewster angle microscopy. Experimental data of the compression are described with a van der Waals model with very good and the fitted parameters were used for calculations of coefficients for different phases found in the compounds investigations. The ability of the two compounds for rotation and disability of the two others is discussed in a context of thermodynamic properties of the monolayers.
Pages: 12354-12363
Journal: LANGMUIR
Volume: 24
ID: ISI:000260508800040
Year: 2008
DOI: 10.1021/la801566a