Research On Biomimetic Synthesis In An Aqueous Organic-additive System

Biomaterials have some unique functions because of their unique and hierarchically ordering morphologies, whose exquisite, highly ordered, and functional architectures have superior mechanical properties as compared with artificially synthetic hybrids. Based on the biological formation mechanisms, synthesis of polymer-inorganic composite materials becomes a promising field in material science research and industry applications. In this dissertation, we developed and enriched the biomineralization method for preparing polymer-inorganic biomaterial materials. First, our progressive achievement is in preparing a series of calcium carbonate with some novel biomimetic structure, which is similar to the hierarchically ordering structure of the natural biomimetic materials, as well as adopting modifications in synthetic conditions to stabilizing the thermodynamically unstable crystal phase. Second, we utilized hydrophilic polymer molecules and other macromolecules that possess functional groups and complicated structures as crystal growth modifier, and we finally obtained a series of calcium carbonate composites with specific morphologies, polymorph and orderly superstructures through altering experimental conditions. The detailed research fruit obtained are summarized as the following:1.Different morphologies of CaCO₃ have been synthesized through controlling the P123 concentration in the triblock copolymer P123 and Mg²⁺ mixed aqueous solution.The morphologies and structures of samples have been characterized by SEM and XRD.The results indicated that the ratios of Ca²⁺and Mg²⁺in the mixture solution drastically changed both the morphology and polymorph of the CaCO₃ crystals.2.In this work the barium carbonate particles were prepared using BaCl₂·2H2Oand Na₂CO₃ by coprecipitation method. Through adding right crystalline controlling modifiers and selecting right amount, the barium carbonate particles with Hollow hexagonal columnar were synthesized. The particles were characterized by SEM and XRD, the results indicated that when crystalline controlling P123 amount was 5g·L^-1, the barium carbonate particles with Hollow hexagonal columnar were synthesized,And the synthesis mechanism of barium carbonate particles with Hollow hexagonal columnar was discussed in this paper.3. We investigated the crystallization of barium sulfate in the presence of polyacrylamide (PAM). The effect of the polymer concentration, temperature, reaction time and the synergic effects between polymers and surfactants on the crystal forms and morphology evolution were investigated in detail. The possible formation mechanisms were discussed.