Abstract
We demonstrate that highly polydisperse colloidal gibbsite platelets easily form an opal-like columnar crystal with striking iridescent Bragg reflections. The formation process can be accelerated by orders of magnitude under a centrifugation force of 900g without arresting the system in a disordered glassy phase. Using transmission electron
microscopy and small-angle X-ray scattering techniques, we find that the forced sedimentation is accompanied by particle size fractionation, leading to inversion of the iridescent colors. The relatively easy self-organization of the polydisperse colloidal particles into opal-like crystals may be explained on the basis of the observed particle fractionation and possibly also on hexatic-like ordering.
Original language | English |
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Pages (from-to) | 11343-11346 |
Number of pages | 4 |
Journal | Langmuir |
Volume | 99 |
Publication status | Published - 2007 |