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Self-assembling Morphologies Obtained from Helical Polycarbodiimide Copolymers and Their Triazole Derivatives
Published on: February 7, 2017
Miscibility between differently shaped mesogens: structural and morphological study of a phthalocyanine-perylene
Gaël Zucchi1, Pascal Viville, Bertrand Donnio
1Laboratoire de Chimie des Polymeres, Universite Libre de Bruxelles, Boulevard du Triomphe, B-1050 Bruxelles, Belgium. gael.zucchi@cea.fr
The Journal of Physical Chemistry. B
|March 24, 2009
Summary
Blends of disk-like phthalocyanine and lath-shaped perylenetetracarboxidiimide form a stable columnar hexagonal mesophase when phthalocyanine is dominant. This liquid crystal blend exhibits enhanced thermal stability and molecular order.
Area of Science:
- Materials Science
- Supramolecular Chemistry
- Liquid Crystals
Background:
- Liquid crystalline materials offer unique self-assembly properties.
- Phthalocyanine and perylenetetracarboxidiimide derivatives are key organic semiconductors.
- Understanding miscibility and phase behavior in blends is crucial for advanced materials.
Purpose of the Study:
- To investigate the thermotropic, structural, and morphological properties of phthalocyanine/perylenetetracarboxidiimide blends.
- To determine miscibility limits and their impact on mesophase formation and stability.
- To explore the influence of blend composition on molecular ordering and dynamics.
Main Methods:
- Differential scanning calorimetry (DSC) for thermal properties.
- Thermal polarized optical microscopy (POM) for mesophase observation.
- X-ray diffraction (XRD) for structural analysis.
- Solid-state nuclear magnetic resonance (ssNMR) for molecular dynamics.
- Atomic force microscopy (AFM) for morphology.
Main Results:
- Full miscibility observed in blends with ≥60 mol% disk-like phthalocyanine, forming a stable columnar hexagonal (Col(h)) mesophase.
- Enhanced thermal stability of the Col(h) mesophase in miscible blends compared to pure phthalocyanine.
- Phase separation occurs below 40 mol% phthalocyanine, leading to less stabilized mesophases and no homeotropic alignment.
- AFM confirmed columnar morphology in phthalocyanine-rich blends.
- ssNMR indicated improved local order parameter in the phthalocyanine columnar phase due to perylene presence.
Conclusions:
- Miscibility significantly influences the stability and self-assembly of the columnar hexagonal mesophase.
- Phthalocyanine-rich blends exhibit enhanced thermal stability and molecular ordering.
- The study provides insights into designing functional organic materials through controlled blending.
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