Session W21: Liquid Crystals III
2:30 PM–5:30 PM, Thursday, March 16, 2006
Baltimore Convention Center Room: 318
Sponsoring Unit:
DFD
Chair: P. Collings, Swarthmore College
Abstract ID: BAPS.2006.MAR.W21.4
Abstract: W21.00004 : Phase morphology of a disk-sphere dyad molecule.
3:06 PM–3:18 PM
Preview Abstract
MathJax On | Off 
Abstract 
Authors:
Li Cui
Jeffrey Collet
Lei Zhu
(Polymer Program, Institute of Materials Science and Department of Chemical Engineering, The University of Connecticut, Storrs, CT 06269-3136)
A disk-sphere dyad molecule was synthesized by attaching a discotic triphenylene molecule to a spherical polyhedral oligomeric silsesquioxane (POSS) molecule via esterification reaction. The self-assembly behavior of the dyad molecule was studied by differential scanning calorimetry, polarized light microscopy, X-ray diffraction (XRD), and transmission electron microscope. Two-dimensional (2D) XRD results showed the dyad molecules self-assembled into a lamellar structure, which composed of a crystalline POSS layer and a discotic-nematic triphenylene double-layer. The POSS layer consisted four layers of ABCA-stacked spherical molecules. The liquid crystalline triphenylene molecules were parallel and staggered in the double-layer. Computer simulation of the XRD intensity confirmed the proposed structural model. Compared with that of the POSS crystal in bulk (melting point at ca 220 $^{o}$C), the melting temperature of POSS crystal was dramatically decreased to 67 $^{o}$C, possibly due to effects of the asymmetry molecular shape and plasticization of the discotic triphenylene moieties between POSS layers.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2006.MAR.W21.4