Affiliation:
1. Department of Chemistry Physical Chemistry I University of Bayreuth Universitätsstr. 30 95447 Bayreuth Germany
2. Jülich Centre for Neutron Science (JCNS‐1/IBI‐8) Forschungszentrum Jülich GmbH 52425 Jülich Germany
3. Bavarian Polymer Institute Bayreuth Center for Colloids and Interfaces, and Bavarian Center for Battery Technology (BayBatt) University of Bayreuth 95447 Bayreuth Germany
Abstract
AbstractThin films comprising mixtures of different colloids provide a simple approach to materials with tunable optical properties. However, the prediction of UV–vis spectra for different compositions in colloidal crystals and glasses is difficult. The degree of disorder, for example, determines whether the optical response is dominated by incoherent scattering, coherent scattering, or Bragg diffraction. Both the volume ratio, as well as the morphology of the individual constituents, influence the properties of the ensemble, which necessitates extensive screening procedures. Here, a method for expediting such a screening approach by means of gradient colloidal crystals and glasses is shown. Continuous composition gradients, combined with local microspectroscopy, allow for the characterization of the entire composition range with high reproducibility, thereby reducing the experimental effort. This is shown for a system of spherical polymer particles with different radii. An optimum of the scattering efficiency in the visible wavelength range is shown close to the order/disorder transition at the edge of the composition range. The high‐throughput screening method presented here can generate large data sets that may contribute to machine‐learning‐enabled optimization of self‐assembled optical materials.
Funder
H2020 European Research Council
Subject
Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials