Template Regulation Of The Water Thermal Preparation Of Calcium Carbonate Biomimetic Materials

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 to 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.In this paper,CaCO3 biomimetic materials were precipitated from Ca(AC)₂/ CO(NH₂)₂ reaction system,using different templates.The samples were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD) and scanning electronic microscopy(SEM). The influence on CaCO₃ of the templates,the concentrations of the templates and the temperature was considered.And we talk about the principium of the reaction.The experiments and results were as follows:1.CaCO₃ was prepared using SDBS of different concentration as templates.The impact on CaCO₃ by the concentration of SDBS at 90,120 and 150℃was studied.When the experimental temperature was controlled at 90℃,aragonite of crystal calcium carbonate was transformed into vaterite.Pure vaterite was obtained as the concentration of SDBS reaches to 2.5 mM.When the experimental temperature was controlled at 120℃and 150℃,aragonite was transformed into calcite,and pure calcite was obtained as the concentrations of SDBS were equal to 1.0 mM and 2.5 mM,respectively.2.CaCO₃ was prepared at different temperatures.The impact on CaCO₃ using SDBS of identical concentration as templates by the temperature was studied.When no SDBS is added, there is no significant impact on the formation with the increasing of temperature;when there is 5.0 mM SDBS,the crystalline forms were changed with the increasing of temperature.Vaterite was transformed into calcite.Pure calcite was obtained at 120℃.3.CaCO₃ was prepared when adding non-surfactantβ-CD.The impact on CaCO₃ byβ-CD concentration was studied.With theβ-CD,both aragonite and calcite were prepared at the same time at 90℃and 120℃,but mainly aragonite.Neither the formation nor the appearance changed.Compared with noβ-CD,there is no obvious difference,only it's more regular.4.CaCO₃ was prepared in the presence of SDBS andβ-CD.The impact on CaCO₃ by the concentration of SDBS and 13-CD was studied.The results are as follows:(1) When there are 2.5 mM SDBS and someβ-CD which is in proportion to the SDBS at 90℃,a mixture of vaterite and calcite were obtained with a lightβ-CD,pure calcite,aragonite and calcite were obtained with the increasing of theβ-CD;When there is no SDBS,pure calcite,aragonite and calcite were obtained with the same concentration ofβ-CD.(2) When there are 1.0 mM SDBS and someβ-CD which is in proportion to the SDBS at 120℃,a mixture of aragonite and calcite were obtained,but mainly calcite.When there is no SDBS,aragonite and calcite were obtained with the same concentration ofβ-CD.5.CaCO₃ was prepared in the presence of SDBS and alcohols.The influence of the existence of the SDBS and alcohols and the different concentration of SDBS was studied.When different alcohols were added,a mixture of calcite and aragonite were obtained.When the identical alcohols were added,a mixture of calcite and aragonite were obtained,too.We also found that when there are alcohols,pure calcite was obtained;when there is no alcohols,a mixture of calcite and aragonite were obtained.The innovation of the paper:CaCO₃ is prepared by a hydrothermal method and the influence on CaCO₃ of the SDBS and temperature was studied;CaCO₃ is prepared by the template of the assembly formed byβ-CD and SDBS,the influence on CaCO₃ of the quantity of theβ-CD was studied;Through the study of the existence and non-existence of the SDBS at different temperatures,we knew that when no SDBS was added,there is no significant impact on the formation with the increasing temperature.