【作者】 张俊英；

【导师】 贝逸翎；

【作者基本信息】 山东大学 ， 高分子化学与物理， 2011， 硕士

【摘要】 纳米材料是一类新颖的功能材料,在生物分离、药物靶向输送、免疫检测及生物传感器等方面具有广阔的应用前景。磁性纳米材料的特性不同于常规的磁性材料,由于其粒径小,比表面积大,且具有优良的磁性能,因此受到许多研究者的青睐,但是相比其他的纳米材料更容易团聚或氧化,因而磁性纳米粒子的改性成为研究的切入点。表面改性是指用物理、化学方法对粒子表面进行处理,有目的地改变粒子表面的物理化学性质,如表面化学结构、表面疏水性、化学吸附和反应特性等。根据纳米Fe0和Fe304粒子表面的特点,通常在粒子表面包覆一层无机或有机物,主要是为了提高其抗氧化性、生物相容性及在使用溶剂中的分散性、稳定性等。此外,也可以根据使用要求,通过表面改性赋予Fe0、Fe3O4粒子表面不同的反应性功能基团(如—COOH、—NH2、—OH等),使其表面功能化而具有不同的使用功能。本论文的主要内容：首先采用微乳液法合成了粒径分布比较窄、分散性好零价纳米铁,再将γ-氨丙基三乙氧基硅烷通过溶胶凝胶法引入到零价纳米铁表面,通过红外光谱分析和透射电子显微镜分析确定了磁性纳米粒子粒径为20～30nm。考察其对Pb2+和酸性大红GR、活性艳红K-2BP的吸附性能和机理。(1)Pb2+的吸附性能和机理研究,实验考察了不同质量的纳米铁、吸附时间、温度和不同比例的γ-氨丙基三乙氧基硅烷改性零价纳米铁对水中铅离子的吸附性能,吸附的活化能为17.30kJ/mol,指前因子k0=18.75min-1。(2)对偶氮类染料酸性大红GR、活性艳红K-2BP的去除性能的研究,确定的最佳PH值4-5,吸附达到平衡时间为12h,浓度为100mg/L的酸性大红和活性艳红水溶液在最佳吸附条件下达到平衡时最大吸附量分别是121.06mg/g和191.5mg/g,且吸附动力学符合langmuir吸附动力学方程,吸附速率方程符合一次动力学方程。其次制备了三乙烯四胺修饰的具有核壳结构的功能化四氧化三铁纳米粒子,考察了其对Cd2+的吸附性能。实验首先采用溶剂热法合成了粒径均一,分散性良好的磁性纳米粒子,又采用溶胶凝胶法正硅酸乙酯水解制备了Fe3O4@SiO2,γ-缩水甘油醚氧丙基三甲氧基硅烷起桥联作用,进而将三乙烯四胺引入到四氧化三铁的表面。制备的结构如下表示：Fe3O4@SiO2@KH-560@TETA。产物进行了红外光谱分析,XRD,热重分析,透射电镜分析和磁性能分析,考察了吸附时间,吸附浓度,溶液的PH值等条件,得到如下结论：产物粒径集中分散在200-300nm,物相为尖晶石结构,核壳结构明显,包覆层的厚度大约在30-50nm,饱和磁化强度仍然为39.21emu/g。确定了对Cd2+最佳吸附PH值为6～7,最大吸附容量为657.9mg/g。实验吸附等温线能很好的符合Freundlich等温吸附模型,吸附动力学符合二次速率方程。更多还原

【Abstract】 Magnetic nano-particles are a kind of novel functional materials, which exhibit extensive application prospect, such as bio-separation, targeted drug delivery, immunoassay and biological sensors and so on. magnetic properties of nano magnetic material is different from conventional magnetic materials, for its small particle size, large surface area and excellent magnetic properties, so it is favored by many researchers. However compared to other nano-materials, they are easier to aggregate with each other or oxidized, thus the modified magnetic nanoparticles are as the starting point of the magnetic nano-materials. Modification means changing the physical and chemistry properties of nano-particles by physical or chemical methods, including the surface chemistry properties, wettability, chemical adsorption and reaction characteristics. According to the surface properties of nano-particles, people usually adopt the method of coating organic or inorganic materials to improve the oxidation resistance, bio-compatibility and stability. The main content of this paper such as following:1.3-aminopropyltriethoxysilane functionalized nanoscale zero-valent iron for the removal of dyes from aqueous solution to adsorb dyes (acid brilliant scarlet GR and reactive brilliant red K-2BP) from aqueous solution. APS-NZVI has shown good adsorption performance at different concentrations of dyes. Under the adsorption conditions of pH 4.5, initial concentration was 100 mg/L, and time is 12h, the adsorption capacity of APS-NZVI for 121.06mg/g and 191.5mg/g, respectively. The results revealed that the adsorption behavior of the dyes on the nano-particles fitted well with the Langmuir model and the sorption kinetics fits well the pseudo-second-order rate equation model.2. In our work, we successfully prepared TETA-coated Fe3O4(?)SiO2 microspheres by using environmentally friendly KH-560 silane coupling agent as the connecting agents between Fe3O4(?) SiO2 spheres and TETA. The advantage of the material are as follows (1) the magnetic core can provide a convenient platform for the facile separation; (2) the silica shell can efficiently prevent the aggregation and chemical decomposition of Fe3O4 in harsh environment; (3) The KH-560 and TETA are without additional toxicity for the further application. (4) This material with excellent solubility are easily scattered, which makes adsorption process easier. (5) This material can be recycled. In this study, silica was selected to encapsulate the obtained magnetite microspheres, because the silica coating could not only effectively screen the magnetic dipolar attraction between magnetite microspheres, which favors the dispersion of magnetite microspheres in liquid media and protects them from leaching in an acidic environment, but also provides them with a silica-like surface, which allows further modification with various groups that are useful for practical applications.更多还原