Tunable morphologies, structure and unusual responsive thermochromism of polydiacetylene supramolelular assemblies

Azobenzene mesogen-substituted polycliacetylene (PDA) which self-assembled into highly ordered lamellar structure and micrometer-sized aggregates structures were investigated in detail by transmission electron microscopy (TEM) as well as X-ray diffraction (XRD). The adjustable molecular structure of diacetylenic monomers allows control of molecular architecture of the supramolecular assembly, resulting in modification of morphology and stacking structure of PDA films. The films form blue phase at room temperature but undergo the well-known thermochromic transition which produce red phase. Due to the strong intermolecular interaction (pi-pi stacking), azobenzene-substituted PDA assemblies shows the enhanced thermal stability, and a reversible chromatic transition at a much higher critical temperature of chromatic transition (105 degrees C for completely reversible thermochromic transition and 150 degrees C for partially reversible thermochromic transition). (C) 2008 Elsevier B.V. All rights reserved.