Study On Effects Of Surface Functional Groups On(Hydroxyl) Oxide Iron Crystallization

Proteins are main materials that regulate life activity, functional groups as the basic component of protein plays a decisive role in adjustment and control of formation of biological mineral compound.Four functional groups were chosen as the molecular template to simulate the mineralization process of biological iron oxide in vitro. Self-assembling monolayers (SAMs)were introduced to investigate effects of hydroxyl (-OH), carboxyl (-COOH), amino (-NH2) and methyl groups (-CH3) of thiol molecules. Water contact angle measurements were used to identify the formation of Au-S bondings. X-ray photoelectron spectroscopy (XPS) assay indicated all the surface densities of different functional groups are similar with the theoretic value,5×1018/m2. Combined with atomic force microscope (AFM) images, distribution of functional groups is composed by the well known ((?)) R30°structure.Three different mineralization systems were applicated to simulating biological environment of iron ore process:FeCl3-HCl mineralization solution, FeCl3mineralized fluid and Fe (OH)3suspension system. Results of characterization of mineralization product on the five sample shown that at the early stage of biomineralization, under three different types of mineralization environment, iron ore formed on the surface which having functional group molecules involved in the regulation, while on different functional surfaces, the products were not of the same morphologies which demonstrates that functional groups played a crucial role in the control of iron mineralization process.