Study On The Mineralization And Mechanism Of Nano Hematite Crystals On The Affection Of Organism Matrix

Biomineralization of iron was discovered later in biomineralization, which were vital ones. There is significant investigation in iron oxide for their stable chemical properties, higher specific surface area, good absorbability and having significant influence on transportation and deposition of negative ion, positive ion and heavy mental ion and organic sequestering agent, especially, the application of the oriented deposition film of iron oxide (such as magnetism, hematite) is under development in the field of information storage materials. Therefore, in this paper we studied the process that soluble organic matter and insoluble organic matter controlled the biomineralization of ferric hydroxide (Fe(OH)₃) and biomimetic synthesis nano hematite (α-Fe₂O₃) crystals based on the basic principles of biomineralization, which has important theoretical significance. The detailed research results obtained are summarized as follows:1. Firstly, the optimal condition ofα-Fe₂O₃ formation was obtained by choosing various pH, negative ion, precipitant and solvent etc to change the environment of the mineralization, and then under the optimal mineralization condition, the soluble organic matter (polyacrylate sodium) was used as an effective soft-template to regulate and control the Fe(OH)3 gel mineralization and biomimetic synthesis theα-Fe₂O₃ crystal. The objective is to study the regulation and mechanism of soluble organic matter on the biomineralization process of Fe (OH) 3 gel. The results showed that the pH value, negative ion, precipitation reagent and type of solvent of mineralized system could influence the biomineralization process of Fe(OH)3 gel. Moreover, under the optimal mineralized condition, soluble organic matter (polyacrylate sodium) controlled the type of crystal, morphology, property and growth patterns of the mineralized products by the way of choosing the mechanism of nucleation and phase transition.2. Under the optimal mineralized condition, the insoluble organic matters (chitosan and polyvinyl alcohol) were used as the hard-template of crystal growth to regulate and control the Fe(OH)3 gel mineralization and biomimetic synthesis theα-Fe₂O₃ crystal. The objective is to study the regulation and mechanism of the insoluble organic matters on the biomineralization process of Fe(OH)3 gel. The results indicated that there were periodic structures in the functional group of insoluble organic matters, which can effectively reduce the potential barrier of crystal nucleation, and then control the process of crystal nucleation and phase transition.3. We have simulated the formation process of the biominerals, regulating and controlling the Fe(OH)₃ gel mineralization and biomimetic synthesis theα-Fe₂O₃ crystal under the co-effection of the above-mentioned soluble organic matter and insoluble organic matter. The objective is to study the regulation and mechanism of organic matter's co-effection on the biomineralization process of Fe(OH)₃ gel. The results indicated that different types of organic matter played different roles in the process of mineral crystal formation. Insoluble organic matters were used as the template controlling the nucleation and phase transition of mineral crystals by the organic/inorganic interface matching; while the soluble organic matter absorbed in the surface of the mineral crystal to control the oriented growth and aggregation of crystal. The co-effection of the both co-control the process of Fe(OH)₃ gel and the crystal type of mineralized products, morphology, property and growth patterns etc.4. We simulated the interaction between polyacrylate sodium, polyvinyl alcohol and ferric oxide crystals by the Molecular Simulation Technology based on the principle of molecular dynamics. The objective is to understand the mechanism that organic matters control the crystal growth at the atomic level. The results showed that there was strong interaction between polyvinyl alcohol and the (110) plane ofα-Fe₂O₃ crystal; the water molecule can favor the binding between polyacrylate sodium and the (104) plane ofα-Fe₂O₃ crystal and accelerate the growth ofα-Fe₂O₃ crystal. The force between polyvinyl alcohol and the (110) plane ofα-Fe₂O₃ crystal, as well as the force between polyacrylate sodium and the (104) plane ofα-Fe₂O₃ crystal are all Coulomb force and Van der Waals force. These forces facilitated the binding between organic matter and crystal surfaces. It was further concluded that organic matters could modulate iron biomineralization process; they control the nucleation and growth of mineral crystals by the different mode of action.