| The most influence of pathogenic microorganism on human beings is the frequent breakouts of the infection diseases. The human health was threatened seriously by the mutated bacteria strains causing by abuse of broad-spectrum antibiotic. For this reason, the antibacterial materials with high efficiency, economy, environment-friendliness and safety were researched by scientists these years.In this work, the anion-emission and storage material, C12A7-O-, was successfully synthesized by sol-gel method. Its structural characteristics, anion-emission and storage features were also observed. The [Ca24Al28O64]4+·4O-(C12A7-O-) particle was also firstly investigated its antibacterial activity and mechanism against bacteria in the solution. Main work was listed:1.The O--containing nanocrystal 12CaO·7Al2O3 (C12A7-O) was firstly synthesized by the citric acid sol-gel combustion method at a lower synthesis temperature (900-1150℃), and the formation of the C12A7-O- material was investigated via X-ray diffraction, thermogravimetric analysis, differential thermal analysis, electron paramagnetic resonance, field emission-scanning electron microscope, and time of flight mass spectroscopy. The C12A7-O- material was synthesized by the citric acid sol-gel combustion method, which contained three main processes, including aluminum oxide formation from aluminum nitrate, calcium oxide formation from calcium nitrate and transformation of aluminum/calcium oxide into Ca12Al14O33.The results showed that the anionic species stored in the C12A7 material was dominated by the active atomic oxygen anions (O-) with a concentration of(1.2±0.3)×1020 cm-3. The emission current density of O- was about 0.89±0.15μA/cm2 at T(sample surface)= 800℃and E(extraction field)= 800 V/cm. The C12A7-O-material was synthesized with a narrower particle size (33-74 nm).2. The C12A7-O- was firstly investigated in the antibacterial test. The results showed that the C12A7-O- nanoparticles also exhibited excellent broad-spectrum antibacterial activity. The unique features of present material such as thermal stable, environment-friendly and safe, could be potentially utilized in antibacterial materials.3. The [Ca24Al28O64]4+·4O- (C12A7-O-) particle was firstly investigated its antibacterial activity against bacteria E. Coli in aqueous solution and phosphate buffered saline (PBS). The C12A7-O- particles were synthesized by gas-solid reaction method with CaCO3 andγ-Al2O3 in a molar ratio of 12:7.The structure change of the C12A7-O- particles was measured by X-ray diffraction (XRD) and electron spin resonance (ESR) after antibacterial test. The results show that the structure of the C12A7-O- particles is completely changed into the structure of (CaO)3Al2O3·6H2O and Al(OH)3. In the C12A7-O- solution (1 mg/mL), the concentration of atomic oxygen anion (O-) in the solution is 4×1016cm-3. In the antibacterial test with the particle concentration of 3 mg/mL in aqueous solution, the bacteria concentration deduces 99.98% in 1 h from the original concentration of 105 cfu/mL. However, when the particle concentration is 1 mg/mL in PBS, the pH is 7.4 and the pH effect of the solution could be neglected, but the bacteria concentration still deduces to 3.7×10(?) cfu/mL from the original concentration in 24 h. In briefly, O- is the main factor in the antibacterial test in the C12A7-O- PBS solution with the neutral pH environment.4. The Ni/ZSM catalyst was synthesized and researched on the steam reforming of bio-oil (Appendix research). This work reported on high catalytic activity of HZSM-5-supported Ni catalyst (Ni/ZSM) synthesized by immersion method, which is successfully applied for steam reforming of light compounds in bio-oil. The influence of the reforming temperature (T), the molar ratio of steam to carbon fed (S/C) and the current (I) in the experiment were investigated. The feathers of the Ni/ZSM catalysts with different loading contents of Ni were investigated by XRD, H2-TPR.. The results show that the carbon conversion and hydrogen yield were remarkably enhanced by the S/C and current. The products of the reaction were also affected. For example, the carbon conversion and hydrogen yield were 81.2% and 69.5%, in the reaction at T= 400℃, S/C=17. The carbon conversion was just 18.9% in the reaction at I=0 A, S/C=3. The carbon conversion and hydrogen yield reached about 100% and 92.6% at I=3.5 A, S/C=17. Without the current at 400℃the selectivity of CO, CH4, CO2 was 6.7%、7% and 86.3% respectively, accompanied by the selectivity decrease of CH4 and CO to 0.6% and 5% respectively, and by the selectivity increase of CO2 to 95% with increasing the current from 0 to 3.5A. |
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