Degradation MXC By Laccase Immobilized On Magnetic Mesoporous And Microporous Composite Material

In this paper, the tubular mesoporous SiO2and spherical SiO2were synthesized using a double template method. Worm-like mesoporous SiO2was synthesized using cationic surfactants template CTAB. The super-paramagnetic Fe3O4nanoparticle was synthesized by thermal decomposition. The synthesized mesoporous SiO2and super-paramagnetic Fe3O4nanoparticle were characterized by XRD, N2adsorption, SEM and TEM. The effects of the structure and morphology of the mesoporous SiO2and magnetic Fe304nanoparticles are investigated.With magnetic mesoporous and microporous composite material as the carrier, glutaraldehyde as crosslinking agent, reverse micelle immobilized laccase. Study on the optimal conditions of immobilization enzyme reaction, magnetic mesoporous and microporous composite material degradation activity and catalytic degradation mechanism of MXC by laccase can be further studied.In the first part, the hollow tubular mesoporous SiO2were synthesized by using Na2EDTA as mineralization agent and catalyst, and CTAB as template agent, TEOS as silica source, in nearly neutral room temperature conditions. The influence of ratio of raw materials, reaction temperature and remove template method on the synthesis of mesoporous structure were studied.In the second part, CaCO3/SiO2core-shell structure are prepared using the needle-like nano CaCO3and CTAB as templates, by the sol-gel method, and followingly orderly tubular mesoporous SiO2were obtained by calcination and soaked in acid solution to remove the template.In the third part, CaCO3/SiO2core-shell structure was prepared using the calcite and CTAB as templates, in alkaline conditions, by the sol-gel method, and followingly orderly sphere-like mesoporous SiO2were obtained by calcination and soaked in acid solution to remove the template. Worm-like mesoporous SiO2was synthesized with F-as the counter ion, and CTAB as templates, under the condition of acid. Study of temperature, pH, counter ion concentration effect on the structure and morphology. The pore size distribution and morphology were characterized. In the fourth part, magnetic Fe3O4particles were prepared through thermal decomposition method, used to Fe(acac)3as the source of iron,1,2-hexadecane glycol as the reducing agent, with oleic acid, oil amine synthesis. Also use co-precipitation method, FeCl3, FeSO4as source of iron, hydrazine hydrate as reductant and precipitant, after hydrophilic nano magnetic Fe3O4particles were formed, add oleic acid for modification, finally lyophobic nano Fe3O4particles were obtained. Nano Fe3O4particles were characterized by TEM, XRD to study of particle size, structure and so on.In the fifth part, immobilized laccase was prepared by co-adsorption of super-paramagnetic particles and laccase on the pore of tubular mesoporous SiO2. Use glutaraldehyde cross-linking, applicate "ship in bottle method", reverse micelle immobilized laccase. Immobilized laccase reaction conditions are optimized, and study the thermal stability of the immobilized laccase enzyme and hollow tubular, sphere, worm-like mesoporous SiO2effect on immobilized laccase.The last part adopts magnetic mesoporous and microporous composite material as the carrier, reverse micelle immobilized laccase to degradate MXC and determine its degradation rate through gas chromatography test. Research of the best condition of degradation of MXC, and continue use of degradation effect of MXC by laccase immobilized on mesoporous silica. The degradation products were characterized by GC-MS, and studied the reaction mechanism.