We report on atomistic simulations related to the nucleation of zinc oxide nanocrystals from ethanolic solution. The underlying mechanisms are explored from the very initial stage of Zn2+ and OH(-) ion association to the formation of nanometer-sized aggregates counting up to 250 ions. The embryonic aggregates consist of zinc and hydroxide ions, only. At later stages of aggregate growth, proton transfer reactions at the aggregate-solvent interface account for the formation of O(2-) ions and induce the precipitation of zinc oxide. After the association of around 150 ions, ZnO domains were found to nucleate in the central region of the [Znx(OH)yOz]2x-y-2z) aggregates. In the course of further ion association and condensation reactions, progressive self-organization leads to an extended core in which the ions are arranged according to the wurtzite structure.

A robotic platform is adopted to conduct a comprehensive solvent engineering for making lead halide perovskites in a high-throughput manner. Deeper insights into the working mechanisms and selection criteria of antisolvents are investigated and summarized. In addition, a reliable antisolvent database is established, and verification tests match well with the theory. Furthermore, our work provides significant guidance for designing functional and environment-friendly mixed solvent systems to fabricate high-quality perovskite materials or devices.

The morphogenesis of calcium oxalate hydrates in aqueous solutions was investigated by varying the pH, oxalate concentration, and the concentration of the sodium salt of polyacrylate (PAA). With increasing amounts of PAA in solution, the shape of tetragonal calcium oxalate dihydrate (COD) changes from bipyramidal through elongated bipyramidal prisms to dumbbells and finally reverts to rodlike tetragonal bipyramidal prisms. PAA is incorporated into the prismatic zones of the growing COD crystals, thereby reducing the growth rate of the {100} faces along the <100> direction. Dumbbells start to develop through "non-crystallographic" branching from the prism faces and the formation of "multiple head" crystals. Adsorption of PAA on the rough surfaces of the splitting individuals supports the selection of new subindividuals and leads to the formation of core-shell patterns. The various shapes and structures of the biomimetic COD/PAA crystals and aggregates are closely related to the well-known "pathologic" individuals observed in the urine of patients with urinary disease (including urinary stones).

This work provides evidence for two-step nucleation in highly supersaturated bulk NaCl solution, using electrostatic levitation combined with Raman/X-ray scatterings.