Mineralization Crystallization And Mechanism Investigation Of Carbonates Mediated In The Presence Of Organic Molecular Template And Solvents Effect

In this dissertation, we have further developed and enriched the biomineralization method to prepare inorganic biomaterial materials, and propose some new and controllable synthesized strategy of fabricating monodisperse microsphere, rod-like and other novelty specific biomimetic structure that is similar to nature in morphology as well as nonclassical crystallization modes—mesocrystal. One makes some progressive achievement in preparing a series of carbonates structure with monodispersity and Hierarchical speciality as well as in mediating the polymorphs of mineral materials and stabilizing the modifications is unstable in thermodynamic. In addition, One utilize hydrophilic polymer molecules and other macromolecules that possessed with part functional groups and complicated structures as crystal growth modifier to investigate different molecules template effect and the synergic effects between polymers and solvents at mild conditions, and finally obtain a series of carbonates composites with specific morphologies, phase behavior and orderly superstructures through altering experimental conditions. The detailed research fruit obtained are summarized as the following:1. One utilize artificial polypeptide block-copolymer—PEG-b-pGlu(18c) as crystal growth template and directing reagents to prepare uniform and highly monodisperse vaterite microspheres and other morphologies of calcium carbonate, such as: flower-like aggregates and Hierarchical dentritic-shaped structure at N,N-dimethyl formamide (DMF)/denonic water(DIW) mixed solution through mediating solvent types and volume effect. And also, the highly monodisperse calcium carbonate microspheres behave better stability in polymorph phase and morphologies, therein, it should be mentioned that, preferred and idealized secondary structures of polymer, DMF/DIW solvents effects originated, hydrogen bonding interaction and the synergic effect between polymer and mixed solvents can play a key role in mediating nucleation, growth, polymorphs phase behavior and self-organization aggregate of minerals.2. One utilize double hydrophilic block-copolymer- poly(ethylene glycol)-b-poly (1, 4, 7, 10, 13, 16-hexaazacyclooctadecan ethylene imine) as crystal growth modifier to produce some better monodisperse shuttle-like structure, high alignment shuttle raft-shaped and other multiple-petals thin flakes barium carbonate structures at DMF/DIW mixed solution system by altering the concentration of polymer, property and volume ratios of mixed solvents. In addition, one have already prepared complicated and hierarchical shuttle-like BaCO₃ aggregates in the presence of DHBC and combination with the specific air/solution interface effect. Therefore, the novel synthesis pathway can also extend to the morphology and structure controllable aspects of other minerals or organic/inorganic hybrid function materials.3. One have fabricated CaCO₃ superstructures with complex form and hierarchical surface texture were mineralized in the presence of peptide type block copolymer poly (ethylene glycol)-b-poly (L-glutamic acid) (PEG-b-pGlu)(18e) as crystal growth modifier in N,N-dimethyl formamide (DMF) solution. Spindle-like CaCO₃ crystals with rather smooth surface and a size of 10μm in length and a maximum diameter of 6μm were mineralized at 24±2℃. Unique and well-defined ellipsoid-like CaCO₃ particles with many similar thorns distributed on the particle surface formed when the mineralization temperature was kept at 14±2℃. Complex column-like CaCO₃ superstructures comprised of many both tiny rods and irregular particles were observed at 4±2℃. Moreover, with biomineralization temperature increasing, CaCO₃ will occur phase transition form mixture of calcite and aragonite to pure calcite, and finally to mixture of calcite and vaterite. In contrast, changing the concentration of polymer can be resulted in phase transition from calcite to a mixture of aragonite and calcite, and then to a mixture of vaterite and calcite. And also, we make a theoretic explanation and analysis to the phase transition occurred at various experimental conditions. Finally, an emergent self-organization process and its combination with an aggregated mechanism for the formation of the complex ellipsoidal superstructures have been proposed. 4. one have obtained barium carbonate (BaCO₃) mineral materials with distinct complicated morphologies in the presence of self-assembling liquid crystalline phases surfactant-P₁₂₃ as structural template through biomineralization reaction pathway. Namely, utilizing the colloid structures formed in the case of proper concentration as precursor template to be successfully fabricate uniform multiple-pores spheres, hexagonal prism-shaped, lantern and plate-like with orderly layered speciality. Therein, we can induce and template the desired morphologies and aggregate structure of barium carbonate by utilizing the kinetic aggregate behavior of colloid formed at aqueous solution; moreover, one have prepared similar layered screw cap, double-taper and shuttle-shaped structures combination with the synergic effect of between P₁₂₃ and mixed solvents. Results demonstrated that different colloid aggregate phase structures of nonionic type surfactant P₁₂₃ formed at aqueous and mixed solutions, respectively, together with the effect of mixed solvents can play a key modulation role in mediating the selective nucleation, controllable growth and crystallization as well as the self-organization construction of the complicated structure of barium carbonate crystal.