Study Of Nano-TiO₂Biomimetic Synthesis And Immobilized Lipase

Nano-TiO2is an important semiconductor material. Due to its excellent characteristics are widely used in paints, cosmetics, catalysts, photographic materials, food packaging, environmental engineering, medicine and other fields. At present, has developed different methods of preparation of TiO2nanomaterials, such as sol-gel method, electric precipitation, hydrothermal, and solvothermal method. And has synthesized a variety of morphologies of TiO2structure, such as nanosheets, nanorods, nanotubes, nanospheres and nanoflowers.In recent years, nano-materials have been widely used in enzyme immobilization. TiO2is non-toxic, biocompatibility, and has good adsorption characteristics to organic matter. Nanoscale TiO2has a large specific surface area, surface tension, surfactants greatly dispersion. Its suspension is stable, not settlement and almost no hardness. It will be good enzyme immobilization carriers. In this study, biomimetic synthesis preparation of different morphologies of nano-TiO2and immobilized lipase. To choose immobilized better carrier for further researching of the optimum conditions of the immobilized and Interfacial properties of immobilized enzyme. The results show that biomimetic synthesis of TiO2nanowires, nanoflowers and nanosheets through the control of experimental conditions and other reagents by using Titanate as tetra butyl titanium source and L-cysteine as template agent. Among them, The nanowire diameter in20-40nm, a length of micron level, and specific surface area reached312.58m2g-1The nanoflower is combination of anatase TiO2and wurtzite ZnO about2-3u m in diameter, mainly containing Zn, Ti, O, and C elements, flower-like morphology consisting of many tens of nanometers thick slices and the specific surface area up to219.54m2g’1; Nanosheets synthesized by adjusting ethylenediamine and water binary system, in addition to study the change of the morphology and crystalline phase during adjustment the experimental conditions.Using three different morphologies of TiO2immobilized lipase, and finding nanowire is better than the others. So, to further research on nanowire TiO2immobilized lipase. Optimized by single factor experiment and response surface experimental design methods, to obtain the optimal combination is Enzyme dosage0.250g, pH7.005, and the immobilization time6.330h. Under this condition, the immobilized lipase theory was80.1207%.Bying SEM、XRD、XPS、FT-IR、UV and the specific surface area analyzer study of the interface characteristics of the immobilized lipase. SEM characterization showed lipase adsorbed onto the nanowire carrier. XRD result, while not ideal, but also to some extent illustrates lipase adsorbed on the carrier. FT-IR showed that the sample lipase characteristic absorption peak after the immobilized. This shows that the lipase has been immobilized to the carrier of nanowire.