The experimental processes are difficult to model by physical laws, because a multitude of factors can intervene simultaneously and are responsible for their instabilities and their random variations. Two types of fac...The experimental processes are difficult to model by physical laws, because a multitude of factors can intervene simultaneously and are responsible for their instabilities and their random variations. Two types of factors are to be considered;those that are easy to manipulate according to the objectives, and those that can vary randomly (uncontrollable factors). These could eventually divert the system from the desired target. It is, therefore, important to implement a system that is insensitive to fluctuations in factors that are difficult to control. The aim of this study is to optimize the synthesis of an apatitic calcium carbonate phosphate characterized with a Ca/P ratio equal to 1.61 by using the experimental design method based on the Taguchi method. In this process, five factors are considered and must be configured to achieve the previously defined objective. The temperature is a very important factor in the process, but difficult to control experimentally, so considered to be a problem factor (noise factor), forcing us to build a robust system that is insensitive to the last one. Therefore, a much simpler model to study the robustness of a synthetic solution with respect to temperature is developed. We have tried to parameterize all the factors considered in the process within a wide interval of temperature variation (60˚C - 90˚C). Temperature changes are no longer considered as a problem for apatitic calcium carbonate phosphate synthesis. In this finding, the proposed mathematical model is linear and efficient with very satisfactory statistical indicators. In addition, several simple solutions for the synthesis of carbonate phosphate are proposed with a Ca/P ratio equal to 1.61.展开更多
Doped calcium carbonate-phosphate is a biocompatible material that influence actively on the osteogenesis, bone regenerate, strengthening of bone and dental tissues including through the skin. A mechanism of the synth...Doped calcium carbonate-phosphate is a biocompatible material that influence actively on the osteogenesis, bone regenerate, strengthening of bone and dental tissues including through the skin. A mechanism of the synthesis reactions of doped nanocrystalline calcium carbonate-phosphate an oscillating type of model for these reactions is proposed. The results indicate that the synthesis involves the formation of hydroxy carbonate complexes from the three calcium carbonate polymorphs (calcite, vaterite, and aragonite) in a solution of ammonium chloride and ammonium carbonate, followed by reaction with orthophosphoric acid. The formation of nanocrystalline calcium carbonate-phosphate doped with Fe2+, Mg2+, Zn2+, K+, Si4+, and Mn2+, has been studied by X-ray diffraction, IR spectroscopy, differential thermal analysis, and energy dispersive X-ray fluorescence analysis. This ensures the preparation of a bioactive material based on octacalcium hydrogen phosphate, and calcium chloride hydroxide phosphates containing cation vacancies. Particle-size analysis data show that the materials contain nanoparticles down to 10 nm in size. Heat treatment of the doped calcium carbonate phosphates produces calcium hydroxyapatite containing cation vacancies, which can be used as a bioactive ceramic.展开更多
文摘The experimental processes are difficult to model by physical laws, because a multitude of factors can intervene simultaneously and are responsible for their instabilities and their random variations. Two types of factors are to be considered;those that are easy to manipulate according to the objectives, and those that can vary randomly (uncontrollable factors). These could eventually divert the system from the desired target. It is, therefore, important to implement a system that is insensitive to fluctuations in factors that are difficult to control. The aim of this study is to optimize the synthesis of an apatitic calcium carbonate phosphate characterized with a Ca/P ratio equal to 1.61 by using the experimental design method based on the Taguchi method. In this process, five factors are considered and must be configured to achieve the previously defined objective. The temperature is a very important factor in the process, but difficult to control experimentally, so considered to be a problem factor (noise factor), forcing us to build a robust system that is insensitive to the last one. Therefore, a much simpler model to study the robustness of a synthetic solution with respect to temperature is developed. We have tried to parameterize all the factors considered in the process within a wide interval of temperature variation (60˚C - 90˚C). Temperature changes are no longer considered as a problem for apatitic calcium carbonate phosphate synthesis. In this finding, the proposed mathematical model is linear and efficient with very satisfactory statistical indicators. In addition, several simple solutions for the synthesis of carbonate phosphate are proposed with a Ca/P ratio equal to 1.61.
文摘Doped calcium carbonate-phosphate is a biocompatible material that influence actively on the osteogenesis, bone regenerate, strengthening of bone and dental tissues including through the skin. A mechanism of the synthesis reactions of doped nanocrystalline calcium carbonate-phosphate an oscillating type of model for these reactions is proposed. The results indicate that the synthesis involves the formation of hydroxy carbonate complexes from the three calcium carbonate polymorphs (calcite, vaterite, and aragonite) in a solution of ammonium chloride and ammonium carbonate, followed by reaction with orthophosphoric acid. The formation of nanocrystalline calcium carbonate-phosphate doped with Fe2+, Mg2+, Zn2+, K+, Si4+, and Mn2+, has been studied by X-ray diffraction, IR spectroscopy, differential thermal analysis, and energy dispersive X-ray fluorescence analysis. This ensures the preparation of a bioactive material based on octacalcium hydrogen phosphate, and calcium chloride hydroxide phosphates containing cation vacancies. Particle-size analysis data show that the materials contain nanoparticles down to 10 nm in size. Heat treatment of the doped calcium carbonate phosphates produces calcium hydroxyapatite containing cation vacancies, which can be used as a bioactive ceramic.
