Controlling the process of crystal growth is of importance to the biomineralization and materials science. In this work, some novel morphology of calcium carbonate (CaCO 3 ) was precipitated in an ethanol-water binary solvent (EWBS) with a CaCl 2 /Na 2 CO 3 reaction system. For the solutions of CaCl 2 /Na 2 CO 3 in EWBS, the alcoholization and hydration of Ca 2+ and CO 3 2were discussed from the radial distribution functions by molecular dynamics simulations, and the number density profiles of water molecules around and ∼15 Å away from CO 3 2were employed to reveal the distribution of water molecules. It is found that EWBS has a divisive effect on Ca 2+ and CO 3 2-, and the local inhomogeneity of EWBS would be enhanced by adding some Na 2 CO 3 into it. This inhomogeneity results in an aqueous two-phase system as x E goes up to 0.7. In addition, the novel morphology of CaCO 3 under different molar ratios of Ca 2+ /CO 3 2and in different mixed solvents were confirmed by XRD and SEM, and the relationships between the morphology of CaCO 3 and the structural properties of mixed solvents were further explored.

Size-controlled, low-dispersed calcium carbonate microparticles were synthesized in the presence of the amphiphilic block copolymer polystyrene-b-poly(acrylic acid) (PS-b-PAA) by modulating the concentration of block copolymer in the reactive system. This type of hybrid microparticles have acid-resistant properties. By investigating the aggregation behaviors of PS-b-PAA micelles by transmission electron microscopy (TEM), the mechanism of hybrid calcium carbonate formation illustrated that the block copolymer served not only as "pseudonuclei" for the growth of calcium carbonate nanocrystals, but also forms the supramicelle congeries, a spherical framework, as templates for calcium carbonate nanocrystal growth into hybrid CaCO(3) particles. Moreover, this pilot study shows that the hybrid microparticle is a novel candidate as a template for fabricating multilayer polyelectrolyte capsules, in which the block copolymer is retained within the capsule interior after core removal under soft conditions. This not only facilitates the encapsulation of special materials, but also provides "micelles-enhanced" polyelectrolyte capsules.

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Keeping stability is important for metastable vaterite to be applied. In this work, crystal evolution of vaterite in water/ethanol binary solvent (WEBS) was investigated. Phase identification was confirmed by XRD measurement. It is found that the stability of vaterite is sensitive to the concentration of surplus CO 3 2-and the ethanol mole fraction in WEBS. The vaterite phase would transform to either aragonite or calcite decided by the surplus CO 3 2-ions or Ca 2+ ions, respectively. SEM observation shows that the polymorph evolution also induced the morphology change.

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