Elucidation of Structural Information of Colloidal Assemblies from Binary Particles using Scattering Techniques*

Self-assembly plays an important role in materials and life sciences, for example, in production of structural colors in various taxa, folding and assembly of proteins in living cells, and creation of metamaterials by self-assembly of complex nanostructures. Previously we have reported a simple one-pot emulsion-based process to form photonic colloidal assemblies called supraballs. In this work, we have measured the small angle neutron scattering from supraball assemblies constructed using binary mixtures of melanin and silica particles. The neutron scattering results can be used to determine the various partial structure factors of the nanoparticles, which is important in understanding scattering of visible light. Designing tunable structural colors is of interest for many applications including cosmetics, paints, and food colorings.