掺杂锡的纳米二氧化钛光催化降解2,4-二硝基苯酚的研究

以T iC l4为原料,在CTAB/正丁醇/环己烷/水组成的微乳液体系中制备了掺杂锡的纳米T iO2粉末,采用X光衍射仪对粉体的粒径和物相进行了表征。通过粉体对2,4-二硝基苯酚的降解情况对其光催化活性进行了测试,结果表明5%Sn4+-T iO2具有良好的光催化氧化性能。

掺杂镨的纳米二氧化钛光催化降解对硝基苯酚的研究

以钛酸丁酯为原料,用溶胶-凝胶(So l-gel)法制备了掺杂镨的纳米T iO2粉末。采用X光衍射仪对粉体的物相进行了表征。样品经500℃焙烧2h后,0.5%(摩尔分数)P r3+-T iO2纳米粉末为单一的锐钛型结构。通过粉体对对硝基苯酚的降解情况对其光催化活性进行了测试,结果表明与纯T iO2相比,P r3+-T iO2的光催化活性有较大提高,当P r3+的掺入量为摩尔比0.5%时催化活性最高。以高压汞灯为光源,对硝基苯酚的初始浓度为50m g.L-1、催化剂0.5%(摩尔分数)P r3+-T iO2投加量为1.0 g.L-1时,对硝基苯酚的光催化降解效果最好。

Characteristics of non-magnetic nanoparticles in magnetically fluidized bed by adding coarse magnets

The fluidization behavior of SiO2, ZnO and TiO2 non-magnetic nanoparticles was investigated in a magnetically fluidized bed （MFB） by adding coarse magnets. The effects of both the amount of coarse magnets and the magnetic field intensity on the fluidization quality of these nanoparticles were investigated. The results show that the coarse magnets added to the bed lead to a reduction in the size of the aggregates formed naturally by the primary nanopartieles. As the macroscopic performances of improved fluidization quality, the bed expansion ratio increases whilst the minimum fluidization velocity decreases with increasing the magnetic field intensity, but for TiO2 nanoparticles there exists a suitable magnetic field intensity of 0.059 6 T. The optimal amounts of coarse magnets for SiO2, ZnO and TiO2 non-magnetic nanoparticles are 40%, 50% and 60% （mass fraction）, respectively. The bed expansion results analyzed by the Richardson-Zaki scaling law show that the exponents depend on both the amount of coarse magnets and the magnetic field intensity.

A comparison of soft magnetic composites designed from different ferromagnetic powders and phenolic resins

Soft magnetic composites （SMCs） were prepared from three different ferromagnetic powder particles： iron powder ASC 100.29, spherical FeSi particles and vitroperm （Fe73CulNb3Si16B7） flakes. Two types of hybrid organic-inorganic phenolic resins modified with either silica nanoparticles or boron were used to design a thin insulating layer perfect- ly covering the ferromagnetic particles. Fourier transform infrared （FTIR） spectrometry confirmed an incorporation of silica or boron into the polymer matrix, which manifested itself through an improved thermal stability of the hybrid resins verified by thermogravimetric-differential scanning calorimetry （TG-DSC） analysis. The core-shell particles prepared from the ferromagnetic powder particles and the modified hybrid resins were further compacted to the cylindrical and toroidal shapes for the mechanical, electrical and magnetic testing. A uniform distribution of the resin between the ferromagnetic particles was evidenced by scanning electron microscope （SEM） analysis, which was also reflected in a rather high value of the electrical resistivity. A low porosity and extraordinary high values of mechanical hardness and flexural strength were found in SMC consisting of the iron powder and phenolic resin modified with boron. The coercive fields of the prepared samples were comparable with the commercial SMCs.

Band Gap Control for （Fe, Ti）-Containing Mesoporous Silica Nanoparticles Using the Photo-Assisted Deposition Technique

It is a great advantage to design advanced materials with outstanding porosity and controllable band gab. In this study, （Fe, Ti）-containing mesoporous silica （x Fe/Ti-HMS） nanoparticles were prepared by a photo-assisted deposition PAD technique, where x is a nominal composition ofFe （l to 4 wt%））. The prepared samples were characterized by DR-UV, XRD, and TEM techniques. The results showed the insertion of Fe into intra-framework of Ti-HMS resulted in a gradual narrowing of the band gap of Ti-HMS samples with increment of Fe wt%. TEM observations reveal that Fe nanoparticles are evenly distributed within Ti-HSM matrix at different Fe wt%. Such results indicate the possibility to control the band gap of a single-site photocatalyst （Ti-HMS） by coupling it with the conventional nano-sized Fe catalysts.

The Preparation and Biocompatibility Study on Fe_2O_3 Magnetic Nanoparticles Used in Tumor Hyperthermia

Objective：To evaluate the in vitro and in vivo toxicity of self-prepared nanosized Fe2O3, which has the potential implication in tumor hyperthermia. Methods： Fe2O3 nanoparticles were prepared by improving co-precipitation, which characterization was detected by TEM, XRD, CMIAS, EDS. MTT assay was used to evaluate the in vitro cytotoxicity test; hemolytic test was carried out to estimate whether it has blood toxicity; Fe2O3 suspended in sterile 0.9% NaCl was intraperitoneally injected into Kumning mouse to calculate the LD50 ; micronucleus （MN） were reckoned to identify whether it is genotoxic. Results：The nanoparticles are brown spherical particles with diameter ranging from 8 to 15 nm, which have good decentralization and stability. The experiments also showed that the toxicity of the material on mouse fibroblast （L-929） cell lines was 0 - 1 degree ; it has no hemolysis activity; LD50 arrived at 5.45 g/kg^-1 after intraperitoneal injection of 1 ml suspension; micronucleus test showed that it has no genotoxic effects either. Conclusion： The results showed that the Fe2O3 nanoparticles are prepared successfully, the self-prepared nanosized Fe2O3 is a kind of high biocompatibility materials and perhaps it is suitable for further application in tumor hyperthermia.