Oriented Nanocrystal Mosaic in Monodispersed CaCO₃Microspheres with Functional Organic Molecules

Abstract

Monodispersed microspheres of vaterite CaCO 3 with a diameter adjusted to the range of 1−10 μm were produced through an amorphous intermediate with polystyrene sulfate. Whereas the microspheres were composed of nanocrystals with a diameter of ca. 20 nm covered with the organic polymer, the crystallographic direction of the entire sphere was evaluated to be macroscopically uniform from its single-crystalline features on polarization anisotropy and morphological evolution into a hexagonal shape with an additional growth process. A particular mosaic with a radially grown backbone structure consisting of oriented nanocrystals was suggested to exist in the microspheres from the electron diffraction patterns. The rigid mosaic framework was covered with a flexible organic component. Thus, various functional organic molecules including hydrophilic and hydrophobic dyes were successfully introduced into the microspheres due to the amphiphilic nature of the organic phase.

Mesocrystals and Their Related Structures as intermediates between single crystals and polycrystals

“…The crystallographic direction of the entire sphere was evaluated to be macroscopically uniform from its single-crystalline features. 102) As shown in Fig. 18 107) and aspartic acid 108) are formed in gel matrices.…”

Mesostructured crystals: Growth processes and features

“…We reported microspheres consisting of vaterite CaCO3 building blocks produced with polystyrene sulfonate (Fig. 12) [98]. The crystallographic direction of the entire sphere was evaluated to be macroscopically uniform based on its single-crystalline features.…”

“…[24] with permission (Copyright 2015 American Chemical Society). amorphous calcium carbonate sphere with polystyrene sulfonate [98]. The crystallographic direction of the entire sphere was regulated through the growth process from an amorphous phase.…”

“…Reproduced from Ref. [98] with permission (Copyright 2012 American Chemical Society). precursor phase would be important for the formation of mesostructured crystals.…”

Application of urea precipitation method in preparation of advanced ceramic powders

“…By taking advantage of those unique conditions, a variety of inorganic particles with uniform size and well-defined morphologies have been synthesized in recent 30 years [29][30][31][32][33][34]. The importance of well-defined fine particles has been recognized in numerous applications.…”