Effect of Polyelectrolyte and Fatty Acid Soap on the Formation of CaCO3 in the Bulk and the Deposit on Hard Surfaces

Effect of Polymer Nano- and Microparticles on Calcium Carbonate Crystallization

Molecular and macromolecular templates are known to affect the shape, size, and polymorph selectivity on the biomineralization of calcium carbonate (CaCO3). Micro- and nanoparticles of common polymers present in the environment are beginning to show toxicity in living organisms. In this study, the role of plastic nanoparticles in the biomineralization of CaCO3 is explored to understand the ecological impact of plastic pollution. As a model study, luminescent poly(methyl methacrylate) nanoparticles (PMMA-NPs) were prepared using the nanoprecipitation method, fully characterized, and used for the mineralization experiments to understand their influence on nucleation, morphology, and polymorph selectivity of CaCO3 crystals. The PMMA-NPs induced calcite crystal nucleation with spherical morphologies at high concentrations. Microplastic particles collected from a commercial face scrub were also used for CaCO3 nucleation to observe the nucleation of calcite crystals on the particle surface. Microscopic, spectroscopic, and X-ray diffraction data were used to characterize and identify the nucleated crystals. The data presented in this paper add more information on the impact of microplastics on the marine environment.

Hierarchical CaCO3 particles self-assembled from metastable vaterite and stable calcite during the decomposition of Ca(HCO3)2

When Ca(HCO₃)₂ solution is put at 80 °C, ACC initially formed grow into calcite, aragonite and vaterite particles. The trunk of snow-shaped particles are self-assembled from hexagonal vaterite particles by one or more steps, followed by the filling in the pores of snow-shaped particles by small crystals.