明胶调控纳米铁矿物生物矿化作用

Effect of Gelatin Modulating the Biomineralization of Iron Minerals

以明胶及葡聚糖为有机基质,在常温中性条件下进行模拟铁生物矿化实验。目的是研究蛋白质及葡聚糖对氢氧化铁凝胶矿化行为的调控作用及其机理,结果表明蛋白质及葡聚糖通过选择成核和相变的机制控制矿化产物的晶体类型、形貌、性质及生长方式等。蛋白质及葡聚糖的活性功能团,能够作为成核位点吸引Fe(Ⅲ)与之发生配位作用而在有机质自组装形成的分子结构中成核结晶,并有一定的取向生长。蛋白质及葡聚糖的分子结构及其性质在矿化过程中发挥了至关重要的作用,矿化体系的pH值、碱度、陈化温度和陈化时间等都能影响氢氧化铁凝胶的矿化行为。最后简要探讨了两者作用机理的不同。

The simulative biominealization experiments were carried out which performed under normal temperature and medium pH. Gelatin and dextran were used respectively as organic matrices in that mineralization systems. The purpose was to study the effects of protein and dextran on modulating the mineralization behavior of Fe（OH）3 gel and its mechanism. The results show that protein and dextran could control the crystal structure, morphology, properties and growth modes of the minerals by selecting the mechanism of nucleation and transformation. The active functional groups of protein and dextran acted as nucleation sites, which can attract Fe（Ⅲ） and complex with them, then the nucleation and crystallization occurred within the self-assembled structure of the organic matrices. So the crystallites had some certain oriented growth. The molecular structure and properties of protein play an important role in the mineralization process. The mineralization behavior of Fe（OH）3 gel was also influenced by pH, alkalinity, aging temperature, aging time etc. Finally the difference of mechanism of protein and dextran is discussed.