Biosynthesis And Characterization Of Mesoporous Silica

In this paper, mesoporous materials, bio-mineralization and biomimetic synthesis are introduced; research and applications of white carbon black materials are reviewed in detail; the feasibility of synthesis of mesoporous silica nanomaterials using microbial mineralization as a template is analyzed. The "enzyme catalyst" theory is introduced into the synthesis of mesoporous silica materials, using natural yeast living cells as a "micro-reactor", to synthesis of mesoporous silica nano-materials using its own biological activity.Using yeast cells as template to synthesize mesoporous silica. We design a orthogonal experiment and define the surface area and oil absorption value as target parameters to select the optimal synthesis conditions. The results show that the surface area and the oil absorption value of the sample can achieve the best overall performance, when the calcination temperature is 550℃, the dosage of yeast cells is 2% (wt%), sodium silicate is 15%, sulfuric acid concentration is 0.15mol/L, and pH value is 9. This condition is the optimum conditions of this experiment. Transmission electron microscopy (TEM) measurements confirm the mesoporous structure of the resulting samples. The Barrett–Joyner–Halenda (BJH) models reveal the existence of mesostructure in the sample, which has a specific surface area of 443.18m2/g and a BJH adsorption average pore size of 6.24nm. We study the process factors on the impact of mesoporous silica through a series of additional experiments. The results show that the surface area and oil absorption values increase first, then decrease with the increase of calcination temperature, the concentration Na2SiO3, and pH. This is consistent with previous results, which further proved that the synthesis conditions before is reasonable.(Chapter II)Adsorption properties and fluorescence properties of mesoporous silica were studied. Immobilization rate ofα-amylase and adsorption rate of methylene blue was calculated by measuring the solution absorbance, respectively. The results show that, immobilization rate ofα-amylase can reach 80% in mesoporous silica materials after 24h, adsorption rate of methylene blue can reach 96% after 120min, both of which show excellent adsorption of silica performance; In addition, the luminescent properties is using fluorescence spectrophotometer and fluorescence microscopy, on this basis, a simple mechanism of its luminescence is studied. (Chapter III) Self-assembly behavior of yeast cells was studied using fluorescence microscopy. crystal nucleation and growth mechanism were explained in the mineralization by HRTEM. On this basis, the mineralization mechanisms have been proposed and mineralization diagram is displayed. (Chapter IV)Mesoporous silica were synthesized using beer yeast as a template. Samples were characterized using TEM, nitrogen adsorption and desorption tests. The results show that the beer yeast plays an important role in mineralization, and mineralization of the mechanism was simply studied by HRTEM. (Chapter V)...