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Updated: Jun 14, 2026
10:35
Using Microwave and Macroscopic Samples of Dielectric Solids to Study the Photonic Properties of Disordered Photonic Bandgap Materials
Published on: September 26, 2014
Shear ordering in polymer photonic crystals.
D R E Snoswell1, A Kontogeorgos, J J Baumberg
1Cavendish Laboratory, University of Cambridge, CB3 0HE Cambridge, United Kingdom.
Summary
Researchers observed colloidal polymeric nanocomposites forming photonic crystals under shear. Flow conditions revealed four distinct crystal growth and decay regimes, validated by simulations.
Area of Science:
- Materials Science
- Polymer Science
- Nanotechnology
Background:
- Colloidal polymeric nanocomposites are advanced materials with tunable properties.
- Shear-induced self-assembly is a key technique for creating ordered structures.
- Understanding the dynamics of crystal formation in viscous melts is crucial for material processing.
Purpose of the Study:
- To investigate the in situ formation and melting of photonic crystals from colloidal polymeric nanocomposites under shear.
- To correlate optical scattering spectra with crystal structure and dynamics.
- To identify and characterize different flow regimes influencing crystal behavior.
Main Methods:
- In situ optical scattering spectroscopy using a multipass rheometer at 150°C.
- Broadband spectroscopy to analyze resonant Bragg scattering peaks.
- Rheological analysis under various flow conditions for a highly viscous, solventless melt.
Main Results:
- Direct observation of photonic crystal formation and melting of monodisperse core-shell particles.
- Identification of four distinct regimes of crystal growth and decay under different flow conditions.
- Correlation of experimental observations with a simple rheological model.
Conclusions:
- Shear flow effectively induces photonic crystal formation in colloidal polymeric nanocomposites.
- The observed crystal dynamics are governed by distinct flow regimes.
- The study provides a validated method for characterizing nanocomposite crystal structures and behavior.
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