In The Organic Substrate And Surfactants Under The Control Of The Biomimetic Synthesis Of Calcium Carbonate,

Mineral Organization is at a wide range of pure in vivo of a variety of biology.Such as bones,teeth,seashells,eggshells,etc.The process of the formation of these minerals Organize in vivo is biomineralization.The significant difference between biomineralization and the general mineralization is that biomineralization produces inorganic minerals through the interactions between organic macromolecules and inorganic ions in the interface by the control of molecular lever.Biomimetic synthesis uses the biomineralization mechanism to produce inorganic materials making use of organic-assembly as templates,to control the formation of the inorganic minerals,and to prepare inorganic materials which have a unique micro-structure.The material has excellent physical and chemical properties.The study of Bionic calcium carbonate is to simulate biological environment,synthesize calcium carbonate crystals which are closer to the forms in the nature,and provide new methods for further in-depth understanding of the mechanism of mineralization and synthesizing new advanced composite materials.CaCO₃ was precipitated with CO(NH₂)₂/Ca(CH₃COO)₂ reaction system.The samples were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD) and scanning electronic microscopy(SEM).The influence on CaCO₃ of surfactant,additives,the ratio of mixed solvent was considered.The obtained results were as follows:1.With tetrahydrofuran as surfactant to the preparation of calcium carbonate crystals.Under the reaction temperature of 90℃and 120℃,the crystalline form of calcium carbonate crystals changes have no impact with the change of the tetrahydrofuran concentration.However,its appearance must have the role of change.With the increase in the concentration of tetrahydrofuran,calcium carbonate crystals gradually smaller.2.To glass as a template,at the presence of tetrahydrofuran,calcium carbonate crystals under the reaction temperature of 90℃has rod-like crystals and spherical crystals.With the reduction of its concentration,the crystalline form of calcium carbonate from aragonite type calcium carbonate to the vaterite type calcium carbonate conversion.Calcium carbonate crystals under the reaction temperature of 120℃has rod-like crystal and the diamond-shaped crystal flake. With the reduction of its concentration,the crystalline form of calcium carbonate from aragonite type calcium carbonate into calcite-type calcium carbonate.In the reaction at glass and tetrahydrofuran the common role of calcium carbonate crystal formation has important implications.3.To sodium dodecylbenzenesulfonate(SDBS) as surfactant,glass chip as a template.With the concentration of THF which is in the solvent increasing.Morphology of calcium carbonate crystals is from the original rod-like structure gradually transformed into spheroidal and spherical.SDBS on the crystalline form of calcium carbonate must play a regulating role However,at the reaction temperature of 120℃,crystalline form of calcium carbonate changes did not happen,on rod-like morphology has only transformed into spherical and spherical ellipsoid.In the reaction at SDBS,glass and tetrahydrofuran the common role of calcium carbonate crystal formation has important implications.4.With dimethyl sulfoxide as surfactant to the preparation of calcium carbonate crystals.Under the reaction temperature of 90℃and 120℃,the crystalline form of calcium carbonate crystals changes have no impact with the change of the dimethyl sulfoxide concentration.With the increase in the concentration of dimethyl sulfoxide,calcium carbonate crystal morphology changed greatly.Morphology of calcium carbonate is from the slender rod into the rod-like with short,until spheroidal,spherical.Description of dimethyl sulfoxide on the crystalline form ot calcium carbonate had no effect.However,changes in morphology have influential.5.To glass as a template,at the presence of dimethyl sulfoxide,calcium carbonate crystals under the reaction temperature of 90℃and 120℃has rod-like crystal and spindle-shaped crystals.With the reduction of its concentration,there is rod-like morphology of calcium carbonate into a spindle,no change in crystalline form.In dimethyl sulfoxide and the glass of the combined effect of the crystalline form of calcium carbonate had no effect.However,changes in morphology have influential.