2021/07/07 by Jürgen Schwarz, Schwarz, Jürgen, P. Leǐderer +3
Materials Science · Chemistry · #Material Dynamics and Properties #Electrostatics and Colloid Interactions #Crystallization and Solubility Studies
paper · pdf · doi:10.48550/arxiv.2107.03381
We determined bulk crystal nucleation rates in aqueous suspensions of charged\nspheres at low metastability. Experiments were performed in dependence on\nelectrolyte concen-tration and for two different particle number densities. The\ntime-dependent nucleation rate shows a pronounced initial peak, while\npost-solidification crystal size distributions are skewed towards larger\ncrystallite sizes. At each concentration, the nucleation rate density initially\ndrops exponentially with increasing salt concentration. The complete data set,\nhowever, shows an unexpected scaling of the nucleation rate densities with\nmet-astability times the number density of particles. Parameterization of our\nresults in terms of Classical Nucleation Theory reveals unusually low\ninterfacial free energies of the nu-cleus surfaces and nucleation barriers well\nbelow the thermal energy. We tentatively attribute our observations to the\npresence of doublets introduced by the employed con-ditioning technique and\nacting as nucleation seeds.\n