2024/04/11 by Marcus U. Witt, Witt, Marcus, G. H. Philipp Nguyen +19
Agricultural and Biological Sciences · Materials Science · #Biocrusts and Microbial Ecology #FOS: Physical sciences #Pickering emulsions and particle stabilization #Soft Condensed Matter (cond-mat.soft)
paper · pdf · doi:10.48550/arxiv.2404.07642
openalex publication_date 2024/04/11 · openalex created_date 2024/04/13 · openalex updated_date 2026/07/31
We study poly-crystalline spherical drops of an aqueous suspension of highly charged colloidal spheres exposed to a colloid-free aqueous environment. Crystal contours were obtained from standard optical imaging. The crystal spheres first expand to nearly four times their initial volume before slowly shrinking due to dilution-induced melting. Exploiting coherent multiple-scattering by (110) Bragg reflecting crystals, time-dependent density profiles were recorded deep within the drop interior. These show a continuously flattening radial density gradient and a decreasing central density. Expansion curves and density profiles are qualitatively consistent with theoretical expectations based on dynamical density functional theory for the expansion of a spherical crystallite made of charged Brownian spheres. We anticipate that our study opens novel experimental access to densi-ty determination in turbid crystals.