Research On Biomimetic Synthesis Of Composite Material 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. We investigated the crystallization of calcium carbonate in the presence of polyacrylamide (PAM) and reported the synthesis of novel core/shell peanut-like assemblies with some cavums. The aggregates were a combination of vaterite and calcite. 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.2. The products of hierachical CaCO₃ multilayer assemblies, multiple layer crystals with smooth films, and cactus-like particles, which are similar to natural mineral biomineral, were synthesized in aqueous solution of the triblock copolymer P123. Additionally, the effect of reaction time, temperature and the concentration of polymer on the crystal morphology and polymorph evolution were investigated in detail. The formation mechanism of aggregates of the hierachical CaCO₃ multilayer assemblies and the embryo multilayer crystals has been studied.3. The effect of Asp and Asp/SDS on the crystal morphology and polymorph evolution was investigated. The possible formation of the petal-like CaCO₃ aggregated was discussed.