稀土亚铬酸盐的合成及介孔材料降低卷烟烟气中铬和镉释放量的研究
发布时间：2018-09-02 08:41
【摘要】：本论文的研究主要包括两个部分：采用水热法合成了稀土亚铬酸盐微米材料,包括正交相的PrCrO3正方体粒子和正交相的NdCrO3椭圆片状粒子,通过X射线光电子能谱、X射线衍射、场发射扫描电镜等方法对材料的结构和形貌进行了表征,优化了合成其较佳结构和形貌的反应参数。提出了各物质不同形貌的可能生长机理,研究了材料的磁性质；采用浸渍法制备了EDTA-4Na/γ-Al2O3介孔复合体纳米材料,通过热重分析、X射线衍射、透射电子显微镜等方法对材料的结构和性能进行了表征。探究了该材料在降低卷烟主流烟气中重金属释放量上的应用。论文的主要研究工作总结如下： (1)采用简单一步水热法合成了正交相的PrCrO3正方体粒子,制备方法简单,产物结晶度较好,通过XRD、 XPS. FTIR、 FESEM等方法对合成的产物进行了表征,确定了合成PrCrO3正方体粒子的较佳反应条件为反应温度280℃,反应时间7天,Pr3+与Cr3+摩尔比1：1,溶液碱度8mol/dm3。研究了PrCrO3正方体粒子可能的形成机理。探讨了其磁性质。结果表明PrCrO3正方体粒子表现出磁相变和负磁化性质。其尼尔温度约为232K,4K下的磁滞回线表明该材料的矫顽力和剩磁分别为17280e和4.88emu/g,与之前报道的PrCrO3材料的尼尔温度、矫顽力和剩磁有小的偏差,这可能是材料的不同形貌和尺寸大小导致的原因,然而更深入地理解其磁性质有待进一步的研究。采用类似的方法制备了正交相的NdCrO3椭圆片状粒子,确定了合成NdCrO3椭圆片状粒子的较佳反应条件为反应温度280℃,反应时间3天,Nd3+与Cr3+摩尔比0.56：1,溶液碱度8mol/dm3。提出了NdCrO3椭圆片状粒子形成的可能机理,研究了其磁性质。 (2)采用浸渍法制备了介孔复合体EDTA-4Na/y-Al2O3,利用TEM、 XRD口TG等对材料的结构和性能进行了表征,将介孔复合体EDTA-4Na/γ-Al2O3添加到滤棒中,制成添加了介孔复合体的特种二元复合滤棒,并制成卷烟,考察其对卷烟主流烟气中铬和镉释放量的影响。结果表明：将介孔复合体EDTA-4Na/γ-Al2O3按每支滤嘴16.25mg的添加量添加到二元复合滤棒中,可使卷烟主流烟气中的铬和镉释放量分别降低‘33.2%和31.1%。同时还研究了介孔复合体EDTA-4Na/γ-Al2O3降低卷烟主流烟气中铬和镉释放量的可能机理,主要有吸附截留和络合截留两种。
[Abstract]:The research of this thesis mainly includes two parts: rare earth subchromate micron materials were synthesized by hydrothermal method, including the PrCrO3 cube particles in the orthotropic phase and the NdCrO3 elliptic sheet particles in the orthotropic phase, and the X-ray diffraction was carried out by X-ray photoelectron spectroscopy (XPS). The structure and morphology of the materials were characterized by field emission scanning electron microscopy, and the optimum reaction parameters of their structures and morphologies were optimized. The possible growth mechanism of different morphologies of various substances and the magnetic properties of the materials were studied. EDTA-4Na/ 纬 -Al 2O 3 mesoporous nanocomposites were prepared by impregnation method and were characterized by thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The structure and properties of the materials were characterized by transmission electron microscopy (TEM). The application of this material in reducing heavy metal emission from mainstream cigarette smoke was investigated. The main work of this paper is summarized as follows: (1) the orthotropic PrCrO3 cube particles were synthesized by a simple one step hydrothermal method. The preparation method is simple and the crystallinity of the product is better. The synthesized product was characterized by FTIR, FESEM and other methods. The optimum reaction conditions were determined as follows: reaction temperature 280 鈩，
本文编号：2218839
[Abstract]:The research of this thesis mainly includes two parts: rare earth subchromate micron materials were synthesized by hydrothermal method, including the PrCrO3 cube particles in the orthotropic phase and the NdCrO3 elliptic sheet particles in the orthotropic phase, and the X-ray diffraction was carried out by X-ray photoelectron spectroscopy (XPS). The structure and morphology of the materials were characterized by field emission scanning electron microscopy, and the optimum reaction parameters of their structures and morphologies were optimized. The possible growth mechanism of different morphologies of various substances and the magnetic properties of the materials were studied. EDTA-4Na/ 纬 -Al 2O 3 mesoporous nanocomposites were prepared by impregnation method and were characterized by thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The structure and properties of the materials were characterized by transmission electron microscopy (TEM). The application of this material in reducing heavy metal emission from mainstream cigarette smoke was investigated. The main work of this paper is summarized as follows: (1) the orthotropic PrCrO3 cube particles were synthesized by a simple one step hydrothermal method. The preparation method is simple and the crystallinity of the product is better. The synthesized product was characterized by FTIR, FESEM and other methods. The optimum reaction conditions were determined as follows: reaction temperature 280 鈩，
本文编号：2218839
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