8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Fri 911:10-14:00P6.27Self-organized structures in chiral microdropletsAlfredo Mazzulla, 1 Gabriella Cipparrone, 2 Raul Josue Hernandez, 2 Alfredo Pane, 1and Roberto Bartolino 21 CNR-IPCF LiCryL Laboratory, Physics Department University of Calabria, Ponte P. BucciCubo 33B 87036, Rende, Italy2 Physics Department University of Calabria, Rende, ItalyIn this work various kinds of chiral microdroplets each one possessing distinctive configurationsof the molecular director are studied. The processes to obtain the droplets and their opticalcharacterization are illustrated and discussed. These complex structures constitute very peculiarmicrosystems, inspiring attractive technological applications. Colloidal anisotropic particlesrecently draw great attention for their possibility to be manipulated with optical tweezers. Ithas been demonstrated their potential use to show the angular and spin momentum of light,the viscosity measurements of liquids on micrometer scale, microfluidic applications, opticalswitches and microlasers. [1-3] The peculiar optical properties of these objects depend from theemulsion preparation standards. The self organized structures have been controlled by means ofboth the chiral dopant concentration and the anchoring conditions at the interface. The resultingmicrodroplets exhibit exciting optical properties, i. e. they show specific kinds of selectivereflection that can be sorted as a radial spot, a localized conical or equatorial. Analyses of theobservations allow to associate the microdroplets to well established chiral structure models [4-7].[1] A. Fernandez-Nieves, Soft Matter 2 105 ( 2006).[2] D. R. Cairns, M. Sibulkin, G. P. Crawford, Appl. Phys. Lett. 78 2643 ( 2001).[3] M. Humar, . Musevic, Opt. Expr. 18 26995 (2011).[4] C. Robinson, Trans. Faraday Soc. 52 571 (1956).[5] Y. Bouligand, and F. Livolant, J. Physique 45 1899 (1984).[6] H. -S. Kitzerow, and C. Bahr, in Chirality in Liquid Crystals (Eds: H. -S. Kitzerow, C. Bahr),Springer, London (2001).[7] J. Bezi, and S. umer, Liq. Cryst. 11 593 (1992).27